Examine source code of SimpleCast Client

{
  "manifest_version": 3,
  "name": "SimpleCast Client",
  "version": "1.3",
  "description": "HTTP and WebRTC compliant Firefox extension for SimpleCast servers. https://github.com/R0NAM1/SimpleCast",
  "icons": {
    "48": "logo-pallete-48.png",
    "96": "logo-pallete-96.png"
  },
  "permissions": [
    "activeTab"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "windowPopup.js"
    ],
    "type": "module"
  },
  "action": {
    "default_icon": "logo-pallete-48.png",
    "default_title": "Open SimpleCast UI"
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "simpleCast@example.com"
    }
  }
}