Examine source code of Twitch Live Extension

{
  "manifest_version": 3,
  "name": "Twitch Live Extension",
  "description": "A browser extension that lists your live followed streamers and sends notifications when they start a new stream",
  "version": "4.3.2",
  "icons": {
    "16": "icon.png",
    "48": "icon.png",
    "128": "icon.png"
  },
  "action": {
    "default_popup": "index.html",
    "default_title": "Twitch Live Extension",
    "default_icon": "icon.png"
  },
  "host_permissions": [
    "https://id.twitch.tv/oauth2/*",
    "https://api.twitch.tv/helix/*"
  ],
  "permissions": [
    "identity",
    "notifications",
    "alarms",
    "storage",
    "idle"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{1ccf7ca1-9c43-4b1d-bd28-6ccb5e6d540b}"
    }
  }
}