Examine source code of Twitch Screenshot

{
  "manifest_version": 3,
  "name": "Twitch Screenshot",
  "version": "1.0",
  "description": "Take clean screenshots of Twitch player without UI elements",
  "browser_specific_settings": {
    "gecko": {
      "id": "twitch-screenshot@example.com"
    }
  },
  "permissions": [
    "activeTab",
    "downloads"
  ],
  "host_permissions": [
    "*://*.twitch.tv/*"
  ],
  "action": {
    "default_title": "Screenshot Twitch",
    "default_icon": {
      "48": "icon48.png"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.twitch.tv/*"
      ],
      "js": [
        "content.js"
      ]
    }
  ],
  "icons": {
    "48": "icon48.png"
  }
}