You can easily log in by clicking on the Profile tab and then select sign in on top. The advantage of logging in to OneFootball on multiple devices is to sync your followed teams and competitions through one account. Keep in mind: You can log in with Facebook, Google, Apple and your email. You must have iOS 13 or later to use the Apple sign-in option.
The app uses the username that is connected to Facebook or Gmail. Therefore, this information cannot be modified by us as it is connected through a third party.