@leocg Ok I tried on Microsoft Edge and it allowed me to activate it. I don't have any other browsers to test so as far as I can tell, only Opera has the issue. At least I have the 2FA now. Thanks.

@leocg That is where the problem is. On the account page. No QR code to scan, have to manually input a code, then it just fails to activate and sends me back around.
Edit: I am using the Opera account to log in to the browser, for all my settings and security stuff to be on the account, hence why I want the 2FA.
I am using Opera browser on a Windows 10 PC, and the Google Authenticator app on an iPhone (The app is not the problem, The account activating on the Opera account page is)

@leocg It is for Opera, for the security on Opera, so not sure how using another browser to do it would make sense. It is part of Opera's browsing settings. I got rid of Chrome cause it stopped working properly and now I only use Opera.

I have tried multiple times to add 2FA to my Opera account using Google Authenticator as instructed, and it keeps taking me round in circles. I get no QR code (just a blank white square) so I have to manually input the massive code on my mobile, then when I finally got the code and typed it in, Opera asked me for my password again and just sent me back around to the start instead of activating.