Hi Surenda

Do you have an example of a website that is not working correctly in Firefox for Android?

What level of Enhanced Tracking Protection do you have set?

Do you have any add-ons installed in Firefox for Android?

I want to us this Search engines because some website are not working properly in google

Just a note, Firefox whether for Windows, macOS, Linux or mobile versions for Android and iOS/iPadOS is a web browser and not a search engine. A search engine is for example google.com, bing.com, duckduckgo.com

To change the search engine in the Firefox web browser for iOS/iPadOS see https://support.mozilla.org/en-US/kb/change-your-default-search-engine-firefox-ios