Rainloop: login "Domain is not allowed"


I have nextcloud 16 and I have installed the app rainloop.
Then I have login with admin/12345 and unfortenly change the wrong config parameter.
Now I can not login with admin/12345 -> Domain is not allowed

I have deactivate and delete the app (I checked -> the folder in apps (rainloop) was realy deleted)

But the config data are not delete. When I reinstall the app rainloop and I tried to login with admin/12345 I get still the error “Domain is not allowed”.

What can I do to setup a whole new rainloop?