MultiOTP, andOTP, TOTP, FreeOTP, and related

How TOTP (Time-based One-time Passwords) work

https://en.wikipedia.org/wiki/Time-based_One-Time_Password

and

Android TOTP password authentication app for 2FA on your Android device

https://github.com/andOTP/andOTP

and

Two-factor authentication for Remote Desktop Web Gateway

https://roman.gallauner.at/?p=886

and

MultiOTP

https://download.multiotp.net/credential-provider/

https://github.com/multiOTP

and

FreeOTP

https://freeotp.github.io/