What do I do if I did not save QR code after initiating two-factor authentication?

Andrew, Thanks for your prompt reply.

Well, the one site I set up for 2FA seems to work. (Tumblr) On iPhone, logged out and rebooted, then restarted and logged back in. 1PW worked flawlessly as usual to fill in username/password, then prompted for 2FA code, which I copied from 1PW. So that seems to work. I would have expected 1PW to fill in automagically without my having to switch apps. But it worked, and I feel like I'll always be able to get back to that site using the backup codes provided by Tumblr.

FYI, when I logged into Tumbler on Safari, after 1PW filled in username/password, the 2FA code was partly filled in with digits that didn't seem match the 2FA code. But I could peek at 1PW, copy the 2FA code and paste it into the login.

So it seems not to matter much that I failed to keep the QR code.

Is it too much for me to expect that 1PW should be filling in the 2FA code by itself without my having to copy and paste them?

I described this in great detail as I don't know what aspect is actually most important for you to see what's going on. You can mark this case closed, although I would like an answer to my question -- I didn't see it in the documentation for 2FA,

Don