I invited someone to my shared album, they accepted and can see it. They cannot see the invite more people option to add more friends to our shared album. How can I let a friend invite additional people to our shared album?

I invited someone to my shared album, they accepted and can see it. However, they cannot see the invite more people option to add more friends to our shared album. How can I let a friend invite additional people to our shared album? The shared album worked, but again, the "invite more people" option does not show for them, even though they have accepted the invite to the shared album. All members of this shared album should be able to invite others to contribute to it. Thanks in advance!