Community → Settings has two fields.
- Membership mode: Open (new members are active), Approval required or Invite only (new members are Pending). The two restricted modes are identical, and there is no invitation feature. With nothing saved the mode is Open. Existing members are unchanged.
- Welcome message: stored, but no page or email shows it to members. Do not rely on it.
Saving needs the community settings permission and a plan with community management.