Examine source code of Refden

{
  "manifest_version": 3,
  "name": "Refden",
  "author": "Refden",
  "description": "Extension for adding references to refden.com",
  "version": "4.0.1",
  "icons": {
    "16": "icon16.png",
    "48": "icon48.png",
    "128": "icon128.png"
  },
  "action": {
    "default_icon": "icon.png",
    "default_popup": "popup.html",
    "default_title": "Refden"
  },
  "background": {
    "scripts": [
      "dist/build/background/bundle.js"
    ]
  },
  "host_permissions": [
    "<all_urls>"
  ],
  "permissions": [
    "storage"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "dist/build/app/bundle.js"
      ],
      "run_at": "document_idle"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "support@refden.co"
    }
  }
}