Examine source code of BBBMessageNotifier

{
  "description": "BBBMessageNotifier",
  "manifest_version": 2,
  "name": "BBBMessageNotifier",
  "version": "1.1",
  "content_scripts": [
    {
      "matches": [
        "*://*/html5client*"
      ],
      "js": [
        "exmess.js"
      ]
    }
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "permissions": [
    "notifications"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{635ca822-3663-4763-a7ae-e9195034ebf9}"
    }
  }
}