Firefox browser doesn't have a search engine it uses default search engine when first installed. If you want a different search engine you need to set that in the settings to use or make a homepage for the search engine site to use.

Mozilla Firefox or Firefox for short is a web browser. A search engine for example is duckduckgo.com, google.com, bing.com

You can change the search engine you want to as default and you can also add search engines.

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

Mozilla who makes the Firefox web browser for desktop and mobile versions for iOS/iPadOS and Android does not have a search engine of their own.