Is the built react code secure against reverse engineering?

I’ve created a react web app that I want to sell to different customers. It is required to run the app on the customers FTP Client.
I want to avoid, that the customer can take the app and sell it to another customer. Thus, it would be necessary to modify the code.
Once the React app is built, it looks very minified and simplified, so at least for me, I could not reverse engineer it.

What is best practice to sell app code to a customer with the ability to self-host it without losing the power of the source code? Is shipping the build content enough?

Answer

They can steal it but it won’t be turning your code back to the source i.e the way it looked and organized into different files before building. They can know and understand how it works and replicate it. And you shouldn’t be worried about that. No body has that kind of time.