See if this link helps: https://www.bing.com/search?q=remove+Qwant+search+engine

In what region/country do you live because in some regions (France) Qwant is one of the enabled built-in search engines ? *https://searchfox.org/mozilla-esr78/source/browser/components/search/extensions/list.json Can't you disable this search engine via "Settings -> Search" ? *https://support.mozilla.org/en-US/kb/change-your-default-search-settings-firefox#firefox:mac:fx78 ---- Note that you are on Mac OS X 10.10 and your OS is no longer supported. The current Firefox 78.15.0 ESR release is the last Firefox version for your OS and you will no longer receive updates.