Today I went to update my wife's and my details in RealMe .... previously used for Passport renewals with no problems.

After logging in, I was told that a 6-digit code had been sent to my "Authentication App".

I'm used to getting a TXT from my bank when accessing via my PC, and also access codes from Google, on my phone.

Does Android have this authentication app built-in, or is this a stand-alone app that is now required?   If so, which one?