There is a c/linkedinlunatics@sh.itjust.works but its not very active… be the change you wish to see!
Go to settings, and in the top left there should be an option for “Wallpapers”, and they should all display there. Make sure your app is fully up to date. They’ve actually added 6 new ones since i tipped a few hours ago.
Oh okay, thank you, I didn’t realize that was the prefix for communities I guess i just assumed it was c/