Examine source code of Audio Booster Pro — Smart Volume Enhancer

{
  "manifest_version": 3,
  "name": "__MSG_extName__",
  "version": "1.0.0",
  "description": "__MSG_extDesc__",
  "default_locale": "en",
  "browser_specific_settings": {
    "gecko": {
      "id": "audio-booster-pro@example.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "16": "assets/icons/icon16.png",
    "32": "assets/icons/icon32.png",
    "48": "assets/icons/icon48.png",
    "128": "assets/icons/icon128.png"
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_title": "Audio Booster Pro",
    "default_icon": {
      "16": "assets/icons/icon16.png",
      "32": "assets/icons/icon32.png",
      "48": "assets/icons/icon48.png",
      "128": "assets/icons/icon128.png"
    }
  },
  "background": {
    "scripts": [
      "background/service-worker.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content/audio-injector.js",
        "content/reconnect.js"
      ],
      "run_at": "document_idle",
      "all_frames": true
    }
  ],
  "permissions": [
    "tabs",
    "storage",
    "alarms",
    "scripting",
    "activeTab"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "commands": {
    "volume-up": {
      "suggested_key": {
        "default": "Alt+Up"
      },
      "description": "Increase volume by 10%"
    },
    "volume-down": {
      "suggested_key": {
        "default": "Alt+Down"
      },
      "description": "Decrease volume by 10%"
    }
  },
  "web_accessible_resources": [
    {
      "resources": [
        "lib/*",
        "assets/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}