Firefox Chromeless Fullscreen

This is a solution to get Firefox (Quantum) working chromeless in fullscreen from startup. This would be useful for setting up a browser for a kiosk.
Create a userChrome.css file:
https://www.howtogeek.com/334716/how-to-customize-firefoxs-user-interface-with-userchrome.css/
Paste this in to the css file:
#navigator-toolbox, #titlebar { display:none; }
Useful to have installed for any other tweaks to the browser style… https://developer.mozilla.org/en-US/docs/Tools/Browser_Toolbox
Add this extension to Firefox:
https://addons.mozilla.org/en-GB/firefox/addon/autofullscreen/
Create a launch agent to fire up the browser to a specific url at startup:
Launch browser on startup (MacOS):
Create a launch agent that runs a bash script at startup that executes:
#!bin/bash
/Applications/Firefox.app/Contents/MacOS/firefox https://example.com