duck duck go
Why do you make me use Google as a search engine on my pc use duck duck go
Opaite Mbohovái (3)
https://support.mozilla.org/en-US/kb/manage-my-default-search-engines-firefox-android
https://support.mozilla.org/en-US/kb/add-or-remove-search-engine-firefox https://support.mozilla.org/en-US/kb/change-your-default-search-settings-firefox
Since you posted about desktop Firefox in the Firefox for Android section. You can add whatever search engine you want and change what is the default search engine.
on my pc i open firefox and duck duck go is my default search engine. On my andriod phone i open firefox and the default search engine is google. I hate google, i hate even more that firefox will not let me change from google to anything else
As I linked earlier it tells you how to add a search engine in Firefox for Android.