"Open your Authenticator app, and enter the number shown to sign in.​​" But I don't get any number

Just got a new iphone, never any problems previously. Started by adding my email to the app and then I was asked to open my Authenticator app and enter the number shown to sign in, while I was in the app but got no number, but the email seems to have been added nonetheless. And then I try to log into the email on my laptop and get the same "Open your Authenticator app, and enter the number shown to sign in.​​" But I dont get any number. I have already deleted the app and added it again and tried this all a few times and went over the most common explanations for this. Anybody had the same problem?