Looking for tutorial on 2FA / oauth2

Some companies i work for have abruptely pushed for 2FA.
Are there some good tutorials for increasing “security” on K9 mail?

MS oauth2 solution, should I do all the step as an end-user?

-> Company A: sends 6 digit code on cellphone or auth
-> Company B: only accept key card or an authenticator

=> main concern: if someone steal your phone you are locked out. That’s why I hate authenticators

I’m a developper but auth is not among my skills yet.
Many thanks.
PS the app is so good, I use it for years - maybe one day I would be able to contribute :smile: