Most instances have a community where users can request the moderator role for inactive or unmoderated communities.

As each instance names these slightly differently, I have created a thread to collect as many as possible.

Lemmy

• !support@lemmy.world
• !support@lemm.ee
• !community_requests@lemmynsfw.com
• !communityrequest@sh.itjust.works
• !community_requests@lemmy.ml
• !communityrequests@lemmy.ca
• !waisenhaus@feddit.org
• !div0@lemmy.dbzer0.com
• !main@lemmy.blahaj.zone
• !adopt_a_community@programming.dev
• !tchncs@discuss.tchncs.de
• !home@lemmy.zip
• !meta@sopuli.xyz (also sopuli’s General matrix room)
• lemmygrad.ml
• lemmy.sdf.org
• !communityrequest@feddit.uk
• feddit.nl
• jlai.lu No community, but a thread here
• beehaw.org
• slrpnk.net
• midwest.social
• infosec.pub
• !meta@aussie.zone
• reddthat.com
• lemmy.today
• feddit.dk
• lemmings.world
• feddit.it
• startrek.website
• mander.xyz
• lemmy.one
• !meta@ani.social
• ttrpg.network
• szmer.info
• lemmy.eco.br
• !community_requests@lemmy.wtf
• discuss.online
• lemmy.kya.moe
• lemdro.id
• lemmy.nz
• !general@lemmy.cafe
• !communityrequests@preserve.games

Mbin

• fedia.io
• kbin.earth
• kbin.melroy.org
• moist.catsweat.com
• feddit.xyz

PieFed

• !piefed_meta@piefed.social
• feddit.online
• feddit.fr
• piefed.au
• piefed.ca
• link.fossdle.org
• tarte.nuage-libre.fr
• pf.korako.me

Please comment below with equivalent communities and I'll add them to the list.

Note: When requesting the moderator role for a community, it is best to do so from a local account (same instance as the community) rather than a remote account. Many people (myself included) have encountered federation issues with some moderation actions when using a remote account.