Scale - how to login to webgui with ldap user

So I set up a FreeIPA and connected my TrueNAS Scale to the ldap service. In the shell I can access the ldap service, I see my user in the local passwd file and can give it the group builtin\_users, but I still can't login to the webgui (wrong username or password). I can't test ssh because that user doesn't have a home directory and I only want to permit ssh login with a key. Can someone give me hint what I am doing wrong? I also can't find any documentation about this, if someone could direct me to the right place, I would greatly appreciate it.