Forum should just show up in groups I would like to have, on my Drupal 8 site, a forum that can be visited only by the members of the group XY; all the other users should not see the forum.

In the permissions I can't find one for viewing the content of the forum.
How can I do that?
I solved the problem with the module Forum Access.


  This module changes your forum administration page to allow you to set
  forums private. You can control what user roles can view, edit,
  delete, and post to each forum. You can also give each forum a list of
  users who have administrative access on that forum (AKA moderators).