cannot remove avira browser safety extension on firefox
I installed avira anti virus years ago and it installed avira browser safety extension to all my browsers by itself, I was using chrome at that time so i only uninstalled it on chrome then recently i opened safari it was there but i was able to uninstall it easily now yesterday i decided to move to firefox and the same extension was there but this time there is no remove button
i tried uninstalling it manually, installing avira anti virus and uninstalling it, removing leftovers of all avira and its extension, uninstalling firefox and reinstalling it, nothing worked, there is something in my system that keeps reinstalling it but idk how to get rid of it, i looked up online there is only for windows chrome
MacBook Pro, macOS Sierra (10.12.6), null