Adding a track to and existing group

I added a group track to some tracks, but later made a new track (let’s call it “B”) on which I recorded a part, and B could benefit from the same sends. Thus I want B added to the same group as the other tracks. I can’t find any option to do that, only to create a new group with B added. How do I route B to the same group track as the other tracks are a part of?

You go to the output routing and assign it to the group.