Endless Loop of Authenticator and Outlook email - can't access either

Question

Hi, hope someone can help as this is doing my head in!

I work for a few different workplaces. One of the workplaces, which I haven't worked for for a long time, has something I am required to fill out. I need to log in to my work Outlook account to do so. We'll call this workplace Big Hotdogs. I open Outlook, type in ******@bighotdogs.com and input my password. The next screen prompts me to open Authenticator to confirm sign in. No problem, this worked all the time so it should work again. But there is no prompt from my Authenticator app, so I open my app to find that there is no ******@bighotdogs.com email address registered in the app. There is only a different workplace account there. No problem, I'll add ******@bighotdogs.com. I click on the 'plus' icon in the corner, type in ******@bighotdogs.com, and select 'work or school account'.

Option one is 'sign in' - I click on that, and it requires me to input my email address and password. So I input the email and password and, despite already being in the authenticator app trying to add this email, it asks me to inout the code from Authenticator. That's not possible, clearly. When I click on 'verify another way' the only two options are approving request via Authenticator or using a verification code, also from Authenticator. Clearly that won't work.

Option two is 'scan QR code' - this open the camera and prompts me to scan a QR code. When I google this issue, it looks like I can get that QR from the set up page in my email account. This, of course, requires me to be signed in to my email account... which I can't be as it asks me for verification from Authenticator, and in order to set up the account on Authenticator, Authenticator requires either a code from itself (for an account that isn't set up so won't generate codes) or requires me to scan a QR code that is generated by being logged into the account that I can't log in to!

I even tried to say I forgot my password to reset it, but the only way I can reset it is by receiving a code from Authenticator...

This is very frustrating, I'm stuck in an endless loop! Any help would be most appreciated.

I am trying to sign in my personal laptop, which is a Mac. I am using the browser, not the app. Not that that changes anything.

Cheers