How you can tell your project will be profitable

I’m days before launch on App Store and I have no clue if my app gonna be nothing or something big.

I can’t find people to test it and tell me if they like it any platform that you put a link blocked you or shadow banned you what was your sign that your project really necessary.

(my project is fixing posture app and from what I Sean gives the most value to the user within the posture apps)