I only found out that this ticket was possible in November, and because subscriptions start at the beginning of each month, you must know ahead of time (otherwise you must wait until the next month.)
I think you also need to order it by the 20th of each month to have it take affect for the next month, but I’m not sure.
Sign-up
I read online that the easiest way to sign-up is the website. So I went to the website and picked the VVB environmental option (VBB-Umweltkarte.)
It was a little concerning because they were showing my yearly total as something like 700 Euro, which would be crazy. But I decided to keep my faith in German bureaucracy. 🙏
Confirmation
Then I got an email with “… in the months of October, November and December 2022, we will deduct EUR 29 each …”
Wait for mail
A few days later I got some mail. I think it is just a physical confirmation that they will bill me.
So at the moment, I’m just waiting for my card to come.