Examine source code of Notification Dashboard

{
  "manifest_version": 2,
  "name": "Notification Dashboard",
  "version": "1.0.1",
  "description": "Monitor and switch to browser tabs with notifications",
  "permissions": [
    "tabs"
  ],
  "commands": {
    "open-dashboard": {
      "suggested_key": {
        "default": "Alt+Shift+D"
      },
      "description": "Open Notification Dashboard"
    }
  },
  "icons": {
    "48": "icon.svg",
    "96": "icon.svg"
  },
  "browser_action": {
    "default_title": "Notification Dashboard",
    "default_icon": "icon.svg"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "notification-dashboard@p145085",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}