Find and open the entry for the site you want to add 2FA to, then click Set Up next to "Verification Code," under Account Options. If the site offers a setup key, enter it in the Setup Key field.

Next, paste in the setup key and then hit OK. Once you do, a verification code will appear. Go back to the website you grabbed the setup key from and enter the verification code to enable 2FA.

This exercise helped me catch expired recovery codes, outdated contact info, and even an instance where I had forgotten to save the 2FA key during setup. Fixing it in advance is way easier than ...