To display results from a different search engine,
  • Navigate to your preferred search engine’s web site.
  • Click or tap the More actions icon (the one with the three dots) in the upper-right corner, and then choose Settings.
         
  • Under the Settings menu, scroll down to the Advanced settings section, then click or tap the View advanced settings button.
         
  • Scroll down to the Search in the address bar with pulldown menu, click or tap the down arrow to the right of Bing, and then click or tap <Add new>.
         

         
 
  • A list of search providers will display. Click or tap to highlight your preferred search engine in the list, and then click or tap the Add as default button.
         

Source: https://techhelpkb.com/how-to-change-the-default-search-engine-in-microsoft-edge/