How to associate a new artist/musician to an existing band

I noticed the band Alcest (https://equipboard.com/band/alcest) didn't have their bassist listed.

I added the bassist here, But I can't figure out how to edit the "Group" section to list the bands they're a part of. https://equipboard.com/pros/indria-saray

Does that information come from some external source? Or is that an edit only an admin can make?

Fixed. Thanks for your patience.

Thanks! :)