Examine source code of GainDial

{
  "manifest_version": 3,
  "name": "GainDial",
  "version": "0.12.0",
  "description": "Controle de volume individual para cada aba, de 0% a 500%.",
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "sites.js",
      "background.js"
    ]
  },
  "action": {
    "default_title": "GainDial",
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/gaindial-16.png",
      "32": "icons/gaindial-32.png",
      "64": "icons/gaindial-64.png"
    }
  },
  "icons": {
    "32": "icons/gaindial-32.png",
    "48": "icons/gaindial-48.png",
    "96": "icons/gaindial-96.png",
    "128": "icons/gaindial-128.png"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "sites.js",
        "page-audio.js"
      ],
      "all_frames": true,
      "match_about_blank": true,
      "run_at": "document_start",
      "world": "MAIN"
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "sites.js",
        "content.js"
      ],
      "all_frames": true,
      "match_about_blank": true,
      "run_at": "document_start",
      "world": "ISOLATED"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "gaindial-f799dafc-4f1b-4593-8a2c-bc8dc6b2dd00@addons.local",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}