Failed to Parse JSON [closed]

I am getting failed to parse JSON on my JS code, and when I tried to print it on console and beautify it on online JSON beautifier. It gives me this error

Parse error on line 1:
...-06-05 11:21:48.0"} ","productSellCatego
-----------------------^
Expecting 'EOF', '}', ',', ']', got 'STRING'

JSON

[{"id":"1" ,"storeName":"MyStore" ,"uniqueStoreCode":"MytURz718" ,"storeDescription":"how about this store" ,"storeStatus":"0" ,"gstinNumber":"mFnbkYGU5BdmijB0ZSp9Xw==" ,"sellerPanNumber":"MNBVK8520U" ,"storeAccountNumber":"Lf4HJliBJzWXIcYUW2CD7Q==" ,"country":"India" ,"state":"Uttar" ,"city":"Ghaziabad" ,"address":"b-1/136 s-1" ,"storeAccountHolderName":"Ramesh Sharma" ,"bankAccountType":"0" ,"addedAt":"2021-08-12 09:40:37.0" ,"storeOwner":{"id":"2", "uniqueUserId":"sec7M3dkH", "firstName":"Ramesh", "lastName":"Sharma", "dateOfBirth":"1979-07-23", "email":"sharmaascent6@gmail.com", "userName":"seller", "status":"0", "role":"1", "country":"null", "state":"null", "city":"null", "zipCode":"null", "address":"null", "gender":"0", "phoneNumber":"+919811708085", "addedAt":"2021-06-05 11:21:48.0"} ","productSellCategory":{"productCatId":"6", "categoryName":"Clothing and Accessories"}" ,"addedAt":"2021-08-12 09:40:37.0" } , {"id":"2" ,"storeName":"MyStore" ,"uniqueStoreCode":"My1mQfYDF" ,"storeDescription":"how about this store" ,"storeStatus":"0" ,"gstinNumber":"h/GcxLRmRljFa0nPE7GtRg==" ,"sellerPanNumber":"MNBVK8520U" ,"storeAccountNumber":"PkEBwQB/eiLktZBe8tDGPw==" ,"country":"India" ,"state":"Uttar" ,"city":"Ghaziabad" ,"address":"b-1/136 s-1" ,"storeAccountHolderName":"Ramesh Sharma" ,"bankAccountType":"0" ,"addedAt":"2021-08-12 09:43:02.0" ,"storeOwner":{"id":"2", "uniqueUserId":"sec7M3dkH", "firstName":"Ramesh", "lastName":"Sharma", "dateOfBirth":"1979-07-23", "email":"sharmaascent6@gmail.com", "userName":"seller", "status":"0", "role":"1", "country":"null", "state":"null", "city":"null", "zipCode":"null", "address":"null", "gender":"0", "phoneNumber":"+919811708085", "addedAt":"2021-06-05 11:21:48.0"} ","productSellCategory":"{"productCatId":"6", "categoryName":"Clothing and Accessories"}","addedAt":"2021-08-12 09:43:02.0" }    , {"id":"3" ,"storeName":"Sharma Ji Store" ,"uniqueStoreCode":"Shlv1BXrS" ,"storeDescription":"This is a beauty products store" ,"storeStatus":"0" ,"gstinNumber":"njauEy1GZ+qEkLt02av/Fw==" ,"sellerPanNumber":"MNBVK8520U" ,"storeAccountNumber":"oc6ZgAfuufHkOt0fyO/lNQ==" ,"country":"India" ,"state":"Delhi" ,"city":"East" ,"address":"gali no.16 adarsh mohhala" ,"storeAccountHolderName":"Ramesh Sharma" ,"bankAccountType":"0" ,"addedAt":"2021-08-12 09:45:58.0" ,"storeOwner":{"id":"2", "uniqueUserId":"sec7M3dkH", "firstName":"Ramesh", "lastName":"Sharma", "dateOfBirth":"1979-07-23", "email":"sharmaascent6@gmail.com", "userName":"seller", "status":"0", "role":"1", "country":"null", "state":"null", "city":"null", "zipCode":"null", "address":"null", "gender":"0", "phoneNumber":"+919811708085", "addedAt":"2021-06-05 11:21:48.0"} ","productSellCategory":{"productCatId":"3", "categoryName":"Beauty"} ","addedAt":"2021-08-12 09:45:58.0" }  ]

My Functions to print strings are

storeOwner

@Override
    public String toString() {
        return "{"id":"" + id + "", "uniqueUserId":"" + uniqueUserId + "", "firstName":"" + firstName
                + "", "lastName":"" + lastName + "", "dateOfBirth":"" + dateOfBirth + "", "email":"" + email
                + "", "userName":"" + userName + "", "status":"" + status + "", "role":"" + role
                + "", "country":"" + country + "", "state":"" + state + "", "city":"" + city
                + "", "zipCode":"" + zipCode + "", "address":"" + address + "", "gender":"" + gender
                + "", "phoneNumber":"" + phoneNumber + "", "addedAt":"" + addedAt + ""}";
    }

stores

@Override
    public String toString() {
        return "{"" +(id != null ? "id":"" + id + "" " : "")
                     +(storeName != null ? ","storeName":"" + storeName + "" " : "")
                     +(uniqueStoreCode != null ? ","uniqueStoreCode":"" + uniqueStoreCode + "" " : "")
                     +(storeDescription != null ? ","storeDescription":"" + storeDescription + "" " : "")
                     +(storeStatus != null ? ","storeStatus":"" + storeStatus + "" " : "")
                     +(gstinNumber != null ? ","gstinNumber":"" + gstinNumber + "" " : "")
                     +(sellerPanNumber != null ? ","sellerPanNumber":"" + sellerPanNumber + "" " : "")
                     +(storeAccountNumber != null ? ","storeAccountNumber":"" + storeAccountNumber + "" " : "")
                     +(country != null ? ","country":"" + country + "" " : "")
                     +(state != null ? ","state":"" + state + "" " : "")
                     +(city != null ? ","city":"" + city + "" " : "")
                     +(address != null ? ","address":"" + address + "" " : "")
                     +(storeAccountHolderName != null ? ","storeAccountHolderName":"" + storeAccountHolderName + "" " : "")
                     +(bankAccountType != null ? ","bankAccountType":"" + bankAccountType + "" " : "")
                     +(addedAt != null ? ","addedAt":"" + addedAt + "" " : "")
                     + (Hibernate.isInitialized(storeOwner) && storeOwner != null ? ","storeOwner":" + storeOwner + " "" : "")
                     + (Hibernate.isInitialized(productSellCategory) && productSellCategory != null ? ","productSellCategory":" + productSellCategory + " ""  : "")
//                   (Hibernate.isInitialized(deliveryStatusSet) && deliveryStatusSet != null ? ", "deliveryStatusSet":" + deliveryStatusSet : "")
                     +(addedAt != null ? ","addedAt":"" + addedAt + "" " : "")
                     + "}t";
    }

Product category

@Override
    public String toString() {
        return "{"productCatId":"" + productCatId + "", "categoryName":"" + categoryName + ""}";

//          return "{"" +(productCatId != null ? "productCatId":"" + productCatId + "" " : "")
//                   +(categoryName != null ? ","categoryName":"" + categoryName + "" " : "")
//                   + "}t";
    
    }

Answer

In your json object is placed with quotes, removing those quotes should make it valid json e.g change ","productSellCategory":"{ to , "productSellCategory": {

your json after removing quotes is

[
    {
        "id": "1",
        "storeName": "MyStore",
        "uniqueStoreCode": "MytURz718",
        "storeDescription": "how about this store",
        "storeStatus": "0",
        "gstinNumber": "mFnbkYGU5BdmijB0ZSp9Xw==",
        "sellerPanNumber": "MNBVK8520U",
        "storeAccountNumber": "Lf4HJliBJzWXIcYUW2CD7Q==",
        "country": "India",
        "state": "Uttar",
        "city": "Ghaziabad",
        "address": "b-1/136 s-1",
        "storeAccountHolderName": "Ramesh Sharma",
        "bankAccountType": "0",
        "addedAt": "2021-08-12 09:40:37.0",
        "storeOwner": {
            "id": "2",
            "uniqueUserId": "sec7M3dkH",
            "firstName": "Ramesh",
            "lastName": "Sharma",
            "dateOfBirth": "1979-07-23",
            "email": "sharmaascent6@gmail.com",
            "userName": "seller",
            "status": "0",
            "role": "1",
            "country": "null",
            "state": "null",
            "city": "null",
            "zipCode": "null",
            "address": "null",
            "gender": "0",
            "phoneNumber": "+919811708085",
            "addedAt": "2021-06-05 11:21:48.0"
        },
        "productSellCategory": {
            "productCatId": "6",
            "categoryName": "Clothing and Accessories"
        },
        "addedAt": "2021-08-12 09:40:37.0"
    },
    {
        "id": "2",
        "storeName": "MyStore",
        "uniqueStoreCode": "My1mQfYDF",
        "storeDescription": "how about this store",
        "storeStatus": "0",
        "gstinNumber": "h/GcxLRmRljFa0nPE7GtRg==",
        "sellerPanNumber": "MNBVK8520U",
        "storeAccountNumber": "PkEBwQB/eiLktZBe8tDGPw==",
        "country": "India",
        "state": "Uttar",
        "city": "Ghaziabad",
        "address": "b-1/136 s-1",
        "storeAccountHolderName": "Ramesh Sharma",
        "bankAccountType": "0",
        "addedAt": "2021-08-12 09:43:02.0",
        "storeOwner": {
            "id": "2",
            "uniqueUserId": "sec7M3dkH",
            "firstName": "Ramesh",
            "lastName": "Sharma",
            "dateOfBirth": "1979-07-23",
            "email": "sharmaascent6@gmail.com",
            "userName": "seller",
            "status": "0",
            "role": "1",
            "country": "null",
            "state": "null",
            "city": "null",
            "zipCode": "null",
            "address": "null",
            "gender": "0",
            "phoneNumber": "+919811708085",
            "addedAt": "2021-06-05 11:21:48.0"
        },
        "productSellCategory": {
            "productCatId": "6",
            "categoryName": "Clothing and Accessories"
        },
        "addedAt": "2021-08-12 09: 43: 02.0"
    },
    {
        "id": "3",
        "storeName": "Sharma Ji Store",
        "uniqueStoreCode": "Shlv1BXrS",
        "storeDescription": "This is a beauty products store",
        "storeStatus": "0",
        "gstinNumber": "njauEy1GZ+qEkLt02av/Fw==",
        "sellerPanNumber": "MNBVK8520U",
        "storeAccountNumber": "oc6ZgAfuufHkOt0fyO/lNQ==",
        "country": "India",
        "state": "Delhi",
        "city": "East",
        "address": "gali no.16 adarsh mohhala",
        "storeAccountHolderName": "Ramesh Sharma",
        "bankAccountType": "0",
        "addedAt": "2021-08-12 09: 45: 58.0",
        "storeOwner": {
            "id": "2",
            "uniqueUserId": "sec7M3dkH",
            "firstName": "Ramesh",
            "lastName": "Sharma",
            "dateOfBirth": "1979-07-23",
            "email": "sharmaascent6@gmail.com",
            "userName": "seller",
            "status": "0",
            "role": "1",
            "country": "null",
            "state": "null",
            "city": "null",
            "zipCode": "null",
            "address": "null",
            "gender": "0",
            "phoneNumber": "+919811708085",
            "addedAt": "2021-06-05 11: 21: 48.0"
        },
        "productSellCategory": {
            "productCatId": "3",
            "categoryName": "Beauty"
        },
        "addedAt": "2021-08-12 09: 45: 58.0"
    }
]