I need help unravelling my sign in details

My MS subscription account name is my AOL email. I use Outlook I have apple phones but the rest is microsoft PC and software. I cannot sign into my outlook on my phone with authenticator because it is not allowed and that is the advice you have given me. I have tried to edit my Aliases to include my outlook account but when I try as prompted to add it it tells me that email is already taken. So it seems like a loop I need help with.