How to access authenticator code when in signing into authenticator app?

I cannot sign into my uni accounts due to authenticator app asking for a verification code from the authenticator app when im using the app?? Sending me on a circular loop of the sane page asking for a code ?? When ask for another way to sign in..only options are to use the authenticator app again. Very frustrating :( need this fixed asap as have exams on Monday! Please halppp!