Examine source code of MeetMeter

{
  "manifest_version": 3,
  "name": "MeetMeter",
  "version": "1.0",
  "description": "Calculate the true cost of your meetings in real time.",
  "action": {
    "default_popup": "popup.html",
    "default_title": "MeetMeter - Meeting Cost Calculator"
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png"
  },
  "permissions": [],
  "browser_specific_settings": {
    "gecko": {
      "id": "meetmeter-addon@prodev.app"
    }
  }
}