Firefox for Android supports adding a custom search engine by URL.

1. Tap the search engine icon in the address bar.
2. Tap Search settings, then Default search engine.
3. Tap Add search engine.
4. Enter the Queye details below and save.
5. Select Queye as the default search engine.

Use these details

• Name: Queye
• Search string URL: https://queye.co/search?s=%s

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