Examine source code of urlings

{
  "manifest_version": 2,
  "name": "urlings",
  "description": "A chat extension that has per-URL channels.",
  "version": "1.0",
  "browser_action": {
    "default_title": "Chat Extension",
    "default_popup": "popup.html"
  },
  "permissions": [
    "tabs",
    "https://urlings-server.onrender.com/",
    "<all_urls>"
  ],
  "content_security_policy": "script-src 'self' https://urlings-server.onrender.com; object-src 'self'",
  "applications": {
    "gecko": {
      "id": "chat-extension@example.com"
    }
  }
}