Let me guess, your version of Debian distro is EOL with no more package updates so now you are trying to use the Firefox tarball version from Mozilla. The Firefox tarball from Mozilla say https://www.mozilla.org/firefox/all/desktop-release/ is just an archive. There is no package or installer setup like you get on Windows. The basics is you extract the tarball then run the firefox script or firefox-bin to start Firefox. You can create desktop or such launcher shortcut to it and there are Firefox icons in the firefox/browser/chrome/icons/default/ folder. The chrome in this case has nothing to do with the Google Chrome browser. Oh and make sure the firefox folder has read/writer permissions for the user to get internal Firefox updates from Mozilla otherwise you will have to do so say as root. An popular place is to have firefox folder in /home/~ if you are the only user. Also this will not just replace any package build of Firefox you have installed (in package manager) on your Linux system as they will be separate.