Do not allow preferences to be changed
Supported on: Firefox 60 or later, Firefox 60 ESR or later
Registry
HKLM
Software\Policies\Mozilla\Firefox\Cookies HKCU
Software\Policies\Mozilla\Firefox\Cookies Value name: Locked
Enabled: Locked = 1
Disabled: Locked = 0
Description
If this policy is enabled, cookie preferences cannot be changed by the user.