Examine source code of MaestroTube - Beta

{
  "manifest_version": 2,
  "name": "MaestroTube - Beta",
  "version": "1.0.6.21",
  "icons": {
    "16": "icons/16.png",
    "32": "icons/32.png",
    "48": "icons/48.png",
    "128": "icons/128.png"
  },
  "permissions": [
    "storage"
  ],
  "web_accessible_resources": [
    "content-scripts/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "strict_min_version": "78.0",
      "id": "{85d4cdd2-5e26-4caa-bbc1-80749367b4f3}"
    }
  },
  "minimum_chrome_version": "87",
  "content_scripts": [
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "run_at": "document_end",
      "css": [
        "content-scripts/content.css"
      ],
      "js": [
        "content-scripts/content.js"
      ]
    }
  ]
}