You can use unbranded builds which are pretty much identical to the stable releases but let you use unsigned extensions. https://wiki.mozilla.org/Add-ons/Exten

You can use unbranded builds which are pretty much identical to the stable releases but let you use unsigned extensions. https://wiki.mozilla.org/Add-ons/Extension_Signing#Unbranded_Builds https://wiki.mozilla.org/Add-ons/Extension_Signing#Unbranded...