The first screen your app shows me is a login screen, without any explanation whatsoever why it would need a login. That’s not a good first impression.

Edit: I realized that my comment is probably more dismissal than intended. The core functionality of your app

„a mobile app using which anyone can generate a 3D Character (within a minute or so) that looks very similar to them with just three photos as inputs. They can also apply different ready-made animations to the model and record some fun, attractive videos with it in Augmented Reality.“

doesn’t inherently need an account to work. So a login/signup screen without anything else as a landing screen isn’t particularly encouraging