Add a user to a group via API?

Development
10

I’m getting 404 on PUT /admin/groups/{group_id}/owners.json on discourse 3.1.0.beta2 (f8863b0f98); is this topic up to date?

EDIT: it seems that one should use PUT /groups/{group_id}/owners.json instead. Additionally the input data is now {"members": "username1,username2,..."}.