Examine source code of PekePBX Browser Sync

{
  "name": "PekePBX Browser Sync",
  "version": "1.1.0",
  "description": "PekePBX Notification Extension",
  "homepage_url": "https://pekepbx.com",
  "options_ui": {
    "page": "options.html",
    "chrome_style": true,
    "open_in_tab": true,
    "browser_style": true
  },
  "background": {
    "scripts": [
      "background.bundle.js"
    ]
  },
  "browser_action": {
    "default_icon": {
      "64": "icon-64.png",
      "128": "icon-128.png"
    }
  },
  "content_scripts": [
    {
      "run_at": "document_start",
      "matches": [
        "<all_urls>"
      ],
      "all_frames": true,
      "js": [
        "contentScript.bundle.js"
      ]
    }
  ],
  "icons": {
    "128": "icon-128.png"
  },
  "manifest_version": 2,
  "content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "permissions": [
    "storage",
    "notifications",
    "contextMenus",
    "activeTab",
    "<all_urls>"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "pekepbx-notifier@barnetik.com",
      "strict_min_version": "57.0"
    }
  }
}