Examine source code of Tab Volume Level Control

{
  "manifest_version": 3,
  "name": "Tab Volume Control",
  "version": "1.1.0",
  "description": "Give every tab its own volume level, and optionally remember it per site.",
  "browser_specific_settings": {
    "gecko": {
      "id": "tab-volume-control@firefox-volume-control",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "permissions": [
    "storage"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "src/shared.js",
      "src/background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "src/content.js"
      ],
      "run_at": "document_start",
      "all_frames": true,
      "match_about_blank": true,
      "match_origin_as_fallback": true
    }
  ],
  "action": {
    "default_title": "Tab Volume Control",
    "default_popup": "src/popup/popup.html",
    "default_icon": {
      "48": "icons/icon.svg",
      "96": "icons/icon.svg"
    }
  },
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  }
}