Examine source code of Session Switcher

{
  "manifest_version": 3,
  "name": "Session Switcher",
  "version": "1.3.0",
  "description": "A Firefox extension for switching between sessions",
  "permissions": [
    "storage",
    "tabs",
    "cookies",
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background/index.js"
    ]
  },
  "action": {
    "default_popup": "popup/index.html",
    "default_title": "Session Switcher",
    "default_icon": {
      "16": "assets/icons/icon-16.png",
      "32": "assets/icons/icon-32.png",
      "48": "assets/icons/icon-48.png",
      "128": "assets/icons/icon-128.png"
    }
  },
  "icons": {
    "16": "assets/icons/icon-16.png",
    "32": "assets/icons/icon-32.png",
    "48": "assets/icons/icon-48.png",
    "128": "assets/icons/icon-128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "session-switcher@fanesp.online",
      "strict_min_version": "109.0"
    }
  }
}