From bleepingcomputer.com
In a Bugzilla report, Mozilla has revealed that they provide enterprise MSI installers starting with Firefox 65. By offering an MSI installer , system administrators can create their own transform files (MST) to easily customize the installation of Firefox in their organization.
Originally targeted to be released for Firefox 64, Mozilla has since pushed the target date for releasing the MSI installers to Firefox 65. These MSI installers have already been created for numerous regions for the Firefox Nightly builds.