Thanks for the quick response.
I think Google switched to an internal push method, baked into Android probabaly. But IIRC they used to do this through the Google Authenticator app as well. Apparently not anymore.
LastPass Authenticator, however, still does this. So do a few other apps I believe.
With LP, I can visit my security settings on a site that supports it. Enable 2FA, scan the QR with the app, login. Then I logout and login again for the first time using TOTP. When the user also has the LP browser extension installed, and also has the credentials of the previous site saved, then the extension will show a popup where you can enable push notifications for future logins.
More info here: https://helpdesk.lastpass.com/en/multifactor-authentication-options/lastpass-authenticator/
Look in the “Enable LastPass Authenticator Push Notifications for Other Sites” section.
I would prefer to keep it within 1 app. I use LP for all my credentials, TOTP and other security stuff. I’d like to avoid having to install another app for this feature.