I cannot access my work email account as my Authenticator app has stopped providing codes.

I cannot access my personal work email account on MS outlook. It used to work well but I had to update my phone and in doing so my authenticator app is no longer linked to my MS work account. Every time I try and log into my outlook account, the system asks for 2FA which is fine, but it only asks for codes from Authenticator. The system used to allow me to use my alternative access email address or phone number. Neither option is available. It only points to the code from the authenticator which I do not have access to. Please help