How to change an account permission, possible or not?

I have set up a new user to my phone. Now I want to add a mail account (IMAP) to this user, but I can’t.
The error message is: “You have disabled a required permission”
That’s right, I have done that before, but now I wont to change the disabeld permission to ‘allowed’, but I don’t know where I con do that.
If that isn’t possible, I would call it a Lineage bug! I am afraid, I have to set up the system again with permission allowed for this user???

Edit: I have found it myself, at the place, where it should be: Settings/Apps/E-Mail/Authorisation (Berechtigungen).
My problem has been, that I allowed some permissions and others I didn’t.