Examine source code of Bookmanager StockChecker

{
  "manifest_version": 3,
  "name": "Stockchecker",
  "version": "2.0.9",
  "description": "Allows Bookmanager users to easily check their stock/pubstock while browsing any web site",
  "icons": {
    "16": "resources/img/icon-16.png",
    "64": "resources/img/icon-64.png",
    "128": "resources/img/icon-128.png"
  },
  "background": {
    "scripts": [
      "browser-polyfill.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "htm.umd.js",
        "react.development.js",
        "react-dom.development.js",
        "browser-polyfill.js",
        "views/scraper/scraper.js"
      ]
    }
  ],
  "commands": {
    "_execute_sidebar_action": {
      "suggested_key": {
        "default": "Ctrl+Shift+F"
      },
      "description": "Open stockchecker sidebar"
    }
  },
  "sidebar_action": {
    "default_title": "Stockchecker",
    "default_panel": "views/sidebar/index.html"
  },
  "action": {
    "default_popup": "views/popup/index.html"
  },
  "permissions": [
    "storage",
    "tabs",
    "contextMenus"
  ],
  "host_permissions": [
    "https://api.bookmanager.com/*",
    "https://bookmanager.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "@tbm_stockchecker"
    }
  }
}