Connecting to iOS client through Good Cloud but account already exists?

Hi, I set up a Nextcloud account, through host The Good Cloud and want to use the iOS app. At the simple sign-up screen, I added my email address but the get the instance ‘Account already exists’. So, I can’t use The Good Cloud, and should opt for a different host?
It’s somewhat confusing, any tips are appreciated.

Can you send a request through the website or private message to me with your email address?

Then we can see what’s wrong.