You can also just store the data encoded in them - it's usually just a string.

I do something similar but sillier. I scan the QR code in a basic QR reader app, then regenerate it using a script I got years ago that renders a QR code using Unicode, then store that in a plaintext file (gpg encrypted) with all my other non-password-manager secrets. I started doing this after I had a bad experience with Google Authenticator not surviving the restore to a new phone.

Or just use Aegis - you can export all your codes as an encrypted backup.

What’s that?

It's an Android app. Its easier to manage OTP codes inside your password manager. Do everything with KeepassXC and KeepassDX. How to sync a file between computers and your phone is left as an exercise to the reader. However I recommend using Syncthing.

No need for screenshots even, right click and Save Image almost always works. I save them all and encrypt them in a separate archive with a different password. No, your probably shouldn’t save them to your password vault (unless you know what you’re doing).

You can also save the TOTP hash instead of the QR code (which basically just contains that hash)

I do the same. But lately, for some but not all sites, I've been putting 2FA codes in Bitwarden and using their app to fill the codes instead of using Authenticator apps.

I did the same, but I had not updated it since 2020, now I can't remember the passphrase I used back then, I probably should have kept a separate paper copy of the passphrase. Or I should have use my GPG private key to do the encryption. It is also possible that my keyboard was not in the right language or I made a typo, I have tested hundred of combinations with no luck so far.