Can’t add 1 month to a moment.js date

I’ve been trying to add a month to a date for a while now but I can’t do it and I have no idea why:

My JSON:

{
      "module": "C Graphical Programming",
      "project": "Back To The Future - MyHunter",
      "start": "2020-12-14",
      "end": "2021-01-03",
      "bttf": true
    }

My code:

timeLineRaw.projects.forEach(element => {
        let timeLineEmbed = new Discord.MessageEmbed();
        timeLineEmbed.setTitle("Test");
        let projectStart = moment(element.start);
        let projectStartPlusOneMonth = projectStart.add(1, 'months');
        if (moment(actual).isAfter(projectStart) && moment(actual).isBefore(projectStartPlusOneMonth)) {
            timeLineEmbed.addField(`${element.module} - ${element.project}`, element.start);
            channel.send(timeLineEmbed);
            db.get('projects').remove({project: element.project}).write();
        }
    });

The output of projectStart and projectStartPlusOneMonth from debugger:

Moment<2020-12-09T00:00:00+01:00> Moment<2020-12-09T00:00:00+01:00>

And if I try to add 1 month to actual date like this moment().add(1, 'months') this works…

Answer

Wrap the variable in another reference of moment like this:

moment(projectStart).add(1, 'months');

moment needs to be referenced everytime that it’s used.