Examine source code of Clutch MultiChat

{
  "manifest_version": 3,
  "name": "Clutch MultiChat",
  "version": "1.0.1",
  "description": "Twitch, Kick e YouTube em um só chat, embutido na página da live — leia e responda sem trocar de aba.",
  "browser_specific_settings": {
    "gecko": {
      "id": "clutchmultichat@clutchchat.pro",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "authenticationInfo"
        ]
      }
    }
  },
  "icons": {
    "48": "icons/icon-48.png",
    "96": "icons/icon-96.png",
    "128": "icons/icon-128.png"
  },
  "permissions": [
    "identity",
    "storage"
  ],
  "host_permissions": [
    "*://*.twitch.tv/*",
    "*://*.kick.com/*",
    "*://*.youtube.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.twitch.tv/*",
        "*://*.kick.com/*",
        "*://*.youtube.com/*"
      ],
      "js": [
        "browser-polyfill.min.js",
        "content.js"
      ],
      "run_at": "document_idle",
      "all_frames": false
    }
  ],
  "action": {
    "default_title": "Clutch MultiChat",
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/icon-48.png",
      "96": "icons/icon-96.png",
      "128": "icons/icon-128.png"
    }
  }
}