I had to uninstalled FireFox because of googletagmanger.com. It was causing me problems with all my websites, favorites, and Proton Mail email. I tried several times to uninstall and reinstall FireFox, but googletagmanger.com kept still showing until I deleted FireFox and stopped using it. I only have one place where I can download the iOS FireFox browser app and that is from the Apple Store. If I tried to type it to get it from online, it takes me to the Apple Store. Some day I would like to go back and get the app but the googletagmanger.com would have to be removed.