DuckDuckGo Browser on Android is designed around DuckDuckGo Search.

1. Open https://queye.co/ in the browser.
2. Use Android's normal share or shortcut tools to add Queye to your Home Screen if you want faster access.
3. If you want Queye as the actual default address-bar engine, use Firefox Android or Vivaldi Android instead.

You can also install the Queye Android app if you want a direct fallback.