Support (lemm.ee)

If you're not seeing the QR code image, something may be blocking it on your end (browser setting too strict, maybe an ad blocker, pihole gone rogue, who knows). It should look like this when you click the button down on the bottom left to begin setup:

The link at the top ("installation link") is oddly named, it's a totp://site:username?secret=xxxxxxx where the value of secret is the TOTP seed (secret key) you could manually cut & paste into an app (Bitwarden OTP, KeepassXC OTP, etc.) if you can't scan the image.

PSA edit: for anyone wondering (I did!) - this screenshot above is "safe", the offered TOTP secret changes on every load of your settings page and clicking that button. If you were thinking about scanning that image for ill gotten gains, it was invalid the minute I closed the Settings tab.