How to enable Global Privacy Control (GCP) in Mozilla Firefox?

"Global Privacy Control (GPC) is a proposed specification designed to allow Internet users to notify businesses of their privacy preferences, such as whether or not they want their personal information to be sold or shared. It consists of a setting or extension in the user’s browser or mobile device and acts as a mechanism that websites can use to indicate they support the specification." -- Source : https://globalprivacycontrol.org/

GPC is inbuilt with Brave and DuckDuckGo browser, and from ve...