Examine source code of HBO Max Volume Control

{
  "manifest_version": 3,
  "name": "HBO Max Volume Control",
  "version": "1.0.1",
  "description": "Control HBO Max volume using mouse wheel.",
  "author": "WebDok",
  "developer": {
    "name": "WebDok",
    "url": "https://webdok.rs/en"
  },
  "homepage_url": "https://webdok.rs/en",
  "icons": {
    "48": "icons/hbo-swcv-48.png",
    "64": "icons/hbo-swcv-64.png",
    "96": "icons/hbo-swcv-96.png",
    "128": "icons/hbo-swcv-128.png"
  },
  "permissions": [
    "activeTab",
    "scripting"
  ],
  "content_scripts": [
    {
      "matches": [
        "*://*.play.max.com/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "host_permissions": [
    "*://*.play.max.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "hbo-max-volume-control@webdok"
    }
  }
}