On Mac, the file goes into Firefox.app/Contents/Resources/distribution. On Windows, create a directory called distribution where the EXE is located and place the file there. Policies can be specified using the Group Policy templates on Windows, Intune on Windows, configuration profiles on macOS, or by creating a file called policies.json.
You should use the officially released versions if you are deploying changes. These policies are in active development and so might contain changes that do not work with current versions of Firefox.
