I have noticed that while there are options to make modded games for yourself in singleplayer, or for other members (or once a week, for everyone) in multiplayer, there is no such option for community levels. I think it's a shame that there isn't any option for it right now, not even as levels playable to members-only, or one that costs coins to play and/or create.
It seems there's already an uservoice thread for it by DanWL from 5 years ago, so I'll link it here:
https://warlight.uservoice.com/forums/77051-warzone-features/suggestions/34715887-allow-single-player-community-levels-to-use-modsI understand that modded games are significantly more resource-intensive than unmodded ones, but I hope there's at least consideration towards making modded community levels a thing. Could also be good publicity for non-members who mainly play singleplayer to be allowed to play a modded level once in a while, and/or after paying a fee (similar to how opening multiplayer modded games to non-members works at the moment), who then could consider buying a membership just to play around in singleplayer with mods at will (which is part of the reason why I purchased one).