Ok um, I usually click the code and it gets copied, then I put it in. I'm not sure if that will help or does anything but copies the code but it's worth a shot?
Open the app on your phone It should say a code needs to be entered. When you click the 2fa section on the forums there is a barcode and a code. Use the code, if you are unable to use the barcode scanner.
Ok so this is how I did it.. I downloaded the app, made an account. I opened the 2fa page on my forums tab. It told me to enter a code into the 2fa, but that isn't what the box is for. The box where you are getting the error is for the token which you will get later.... I entered the code into the app. Then it made my account and got me a token which I entered into the place where you are getting the error.
CASSIE ITS RLY EASY PLS RELOAD THE 2FA PAGE WHEN IT SAYS ENTER A CODE ON THE 2FA PAGE ENTER THE CODE AND THEN U ENTER THE TOKEN INTO THE FORUMS OMG OMG PLS