Can't log in with my 2-factor authentication

I am logged in on an old PC as well as on my iPhone

Now I have a new computer, where I try to log in.
When I do, it asks for a 6-digit code from my authenticator app.
In my app, no code comes up (I also can't remember that I configured any app for 2-factor specifically for Facebook)

My option is to "authorize from other device".

But, on my old PC or iPhone no request comes up to approve this.

I've also tried turning off 2-factor authentication via the devices I'm logged in to, but then it wants the 6-digit code, which I can't access. Alternatively, I enter a reserve code. But to be able to access a backup code, I need to be able to log in with 2-factor authentication on another device.

Gahhh, been working on this part 22 problem for a few days now. And via Facebook I haven't found anything that helps.

Please help