There's a prominent search field and button at https://gnusocial.no/search/people?q=lohang, although there may not be any link to get there from the main page. FWIW, there are also search URLs for notices https://quitter.no/search/notice?q=search+box and groups https://quitter.no/search/group?q=coffee and you can search for hashtags with https://quitter.no/tag/hashtag