Examine source code of FullPageCapture

{
  "manifest_version": 2,
  "name": "FullScreenie",
  "version": "1.0.4",
  "description": "Capture a full-page screenshot and copy it to your clipboard.",
  "permissions": [
    "<all_urls>",
    "clipboardWrite"
  ],
  "browser_action": {
    "default_icon": {
      "128": "icons/icon-128.png"
    },
    "default_title": "Full Page Screenshot"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "fullscreenie@parkerscode",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}