Firefox for Enterprise Isithangami Sokwesekwa

I am trying trying to install the keeper extension via intune but am having trouble with the oma-uri. It looks right to me but I might be missing something. Prior to running this I followed https://mzl.la/3vYAIYT and added the Firefox ADMX. Both run successfully but it does not add the extension. Firefox version 116.0.3

OMA-URI: ./Device/Vendor/MSFT/Policy/Config/Firefox~Policy~firefox~Extensions/ExtensionSettings

String: <enabled/> <data id="ExtensionSettings" value=' {

 "*": {
   "blocked_install_message": Opps, this may have been a mistake reach out to IT.",
   "install_sources":["about:addons","https://addons.mozilla.org/"],
   "installation_mode": "allowed",
   "allowed_types": ["extension" ,"theme"]
 },
 "KeeperFFStoreExtension@KeeperSecurityInc": {
   "installation_mode": "normal_installed",
   "install_url": "https://addons.mozilla.org/firefox/downloads/latest/keeper-password-manager/latest.xpi",

"default_area": "navbar"

 },

}'/>

Hi there,

I'm playing with policies.json on Linux/Ubuntu now, trying to improve my knowledge of Firefox customization through different policies and user interaction after the Firefox deployment. I added a custom bookmark and extension, which show and install okay when I restart the browser. But when I delete them from within the browser and restart Firefox, they show up again. To avoid this, I can delete /etc/firefox/policies/policies.json after the Firefox deployment. Hence my questions:

• Is the deletion of the JSON file after the Firefox deployment a reasonable option at all?
• If yes, how can I automate the process silently, without user interaction?
• If no, what would be your advice to let users modify the browser settings like removing extension(s) or bookmark(s) set in policies.json so that they do not reappear after the browser restart?

Thank you! Rustam