In the previous article you have learn, How to block extensions on chrome browser and in this article you are going to understand to prevent extensions on another popular browser called Mozilla Firefox.
Check the version of the browser and download the policy templates according to your browser version.

Once zip file downloaded, extract file, find mozilla.admx file and copy to your AD server under windows -> PolicyDefinitions section. This will load the policy templates for the browser to manage it from Domain controller.

After putting ADMX file under policy definitions . you will get an option of Mozilla for the browser customization. after completing the above process your are ready to make changes on your browser. To do that,
Go to -> Computer Configuration -> Policies -> Administrative Templates: Policy definitions -> Mozilla -> Firefox -> Addons -> Right click on “Allow Add-on installs from websites” and go to properties

Here you will be able to see same as below image where you will find an option of “Disabled“. click on Disabled option, Appy and save.

After applying the changes. you are ready to link your GPO to the computers. as because this GPO is created for the computer. Go to your OU having those computers where you want to apply and disable the extension installations.
Wait approximately 40 minutes to apply changes automatically by the GPO or run gpupdate on you AD along with the computers to take immediate effect.
In this article you have learn, how to create GPO to prevent installing extensions on your Mozilla browser centrally from active Directory. You also might be interested to learn, how to Prevent installing extension on edge browser.