My experience: Beehaw/Lemmy is using a SHA256 hash for the secret key. A lot of 2FA apps only support SHA1. So you’ll need to find one that supports SHA256. I used Google Authenticator. I thought I also saw that Microsoft Authenticator works too. Storing in Bitwarden doesn’t work.
Good luck.
I would definitely do all my testing in private browsing or another browser while leaving a browser window logged in to disable 2FA should you need to.