http://tth4he7kdfmfwq2k7yaj2ggjdva7rdpbch42q6xgoorbabjeklyfbmyd.onion/tor66-an-onion-indexer-and-search-directory
So, while TOR v3 cannot be easily indexed by bot crawlers, it can still function as a search engine by crowdsourcing content. The admins clearly post a contact email for “users, and .onion service-providers, or tech-enthusiasts, LE”.