Maybe Duck-Duck-Go need to have a !bang search modifier for Lemmy. https://duckduckgo.com/bangs

Most likely not feasible, because what the bangs do is passing site:domain.com to the search result. As you know, Lemmy does not have a singular domain name so this won’t work for it. As a matter of fact, there is a bang for Mastodon, but it only searches the biggest instance, mastodon.social.