BRUSSELS—DuckDuckGo and three other search engine rivals to Google on Thursday urged EU lawmakers to take action against the Alphabet Inc.’s unit via new tech rules, saying they have yet to see positive results from an antitrust ruling against Google Inc. The European Commission in 2018 levied a record 4.24- billion-euro ($5 billion) fine on Google for unfairly using Android to cement the dominance of its search engine and ordered it to ensure a level playing field for rivals. Google subsequently made changes and four months ago said it would let rivals compete for free to be the default search engines on Android devices in Europe. U.S. search engine DuckDuckGo, Germany’s Ecosia, and French peers Qwant and Lilo said lawmakers should use tech rules drafted by EU antitrust chief Margrethe Vestager called the Digital Markets Act (DMA) to ensure competition. “Despite recent changes, we do not believe it will move …