Hello!
The V12 deck should be in your “AnKing” deck. All your previously V11 cards have been updated to V12. You can either keep this deck or move all V12 cards to another new deck. You can see how to do this here.
Regarding tags, go to Browse → tags on the left hand side → right-click and delete the V11 tags. That way you only see V12 tags
The AMBOSS addon will work with your version, you can also update to 23.10. We recommend 2.1.64 but you can safely upgrade to 23.10 if you would like (I’m currently running that version with no issues!)
You can install the AMBOSS addon here. It will work with your version (2.1.66) and 23.10 if you wish to upgrade
Let us know if you need anything else!