This is not a problem, but a solution. Lots of people are wondering how to make a login system that saves progress. I have made an app game that does this. I also am currently making youtube videos, and have made 2 methods. If you need help in this topic, see my youtube channel: https://www.youtube.com/channel/UCuO0NCqfd9OYm2AaP3G9kog?app=desktop