Just collect a small amount of sats from the attendees, either per event, or as a community fee
nostr:nprofile1qqs2rx4daefmcuwjttl0xegx0guh3tps64fq6dhv3nr56aagw2hhxkgprpmhxue69uhhwmm59eeh2er0vdshymr0wvhxxmmdqy8hwumn8ghj77npwqh8wct5vd5qvs052a supports the former right now, and soon will support memberships and communities so organizers can properly fund their operation