Thank you so much for the very clear images @smrtey
This helps a TON. One thing I will add is that the group must be created from the outset with Visibility of the group = EVERYONE.
I tried changing the visibility of an existing group to Visbility = Everyone, but it didn’t seem to stick. Also, the checkbox for the “Allow users to send membership requests to group owners” got greyed out and not selectable. Don’t know why that happened either.
Anyway, I deleted the original group and started over and it works now.