In groups where owners approve membership requests, there is a pending status that happens between the time the request to join the group is submitted and the time the owner approves or denies the request. This is when the membership is awaiting approval.
While the member prospect waits for the owner of the group to see their new member request, they’ll see the new group in their group list, however if selected, they will receive a message that their membership request is awaiting approval.
Once the owner sees the new member request and approves, the member prospect will receive a push notification that their member request has been approved and they can now access the group.