Examine source code of Rating Captain

{
  "version": "1.0.0",
  "manifest_version": 2,
  "homepage_url": "https://ratingcaptain.com",
  "name": "Rating Captain",
  "description": "This is the Rating Captain browser plugin. This simple plugin allows you to check the Reviews Audit score of any website you visit.",
  "icons": {
    "144": "images/ic_launcher.png"
  },
  "browser_action": {
    "default_icon": "images/ic_launcher.png",
    "default_title": "RatingCaptain",
    "default_popup": "popup/popup.html"
  },
  "background": {
    "page": "background/background.html"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "common.js"
      ]
    }
  ],
  "permissions": [
    "activeTab",
    "https://rc-data-companies-um6ofthcmq-ez.a.run.app/*",
    "storage",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{b12fb6ad-b4c0-4b94-ae67-ba5a3cc7f45b}"
    }
  }
}