What does 2 step verification in Outlook 2021 look like?

I am using Outlook 2021 with POP accounts and one step verification.  I have also just setup Exchange accounts for the same email accounts in prep for the two step verification (Sept 16).  I then turned on two step verification in my Outlook email account.  After sending an email to the account that has two step verification on, and opening in Outlook 2021, it behaves the same with both (POP and Exchange) as it always done.  There are no extra steps.

- How come the POP account works with two step verification on?

- There weren't any extra steps for two step verification.  Why?

- Related to the question above, what does sending and receiving email look like with two step verification?