Problem in mobile application

I installed nextcloud on a server all is well
but in the mobil application ans computer application I have the domain name next to login
how to leave that the email address

My domain
in applciaition I have

I’m sorry if I misunderstand your question:

As far as Nextcloud is concerned is your username so it should display as

Are you using the IMAP authentication backend to login using your email address? If so you can hide the

but it’s not for IMAP but I use local accounts and OpenLdap
for example

my website http: /
my login
but on the app shows me login @ @