Clicking Invite (from the Timeline card, 5.2) opens two paths:

  • Share invitation — a course ID/link you distribute yourself; learners who use it request to join. This is what feeds the public Landing Page (5.6).
  • Add single learner — the admin-initiated path, by email or phone, which opens the enrollment wizard (5.4).

There's no bulk CSV enrollment specific to a Group course the way there is for Users generally (3.2) — just the two paths above, from inside the course.