Hey, how i use my Email in the app…
Screenshot_20191201-192346_Roundcube|230x500
Looks like you‘re using a mobile app that supports roundcube?
I would recommend you use the official webmail, which you can find in the panel.
Is this the app you’re trying to setup?
To be honest, the app looks a bit sketchy. It does not appear to be developed or endorsed by the official RoundCube developers, and the app just looks like a web view with some mobile tweaks. The ratings should be warning enough.