Examine source code of Work Hour Calculator

{
  "manifest_version": 3,
  "name": "Work Hour Calculator",
  "version": "1.0",
  "description": "Shows how many work hours an item costs",
  "permissions": [
    "storage",
    "tabs"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{3b0502c1-b455-4c8b-b200-b888dcd11ff7}",
      "strict_min_version": "58.0"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.solotodo.cl/*",
        "*://*.amazon.com/*",
        "*://*.amazon.co.uk/*",
        "*://*.amazon.ca/*",
        "*://*.amazon.es/*"
      ],
      "js": [
        "work-hour.js"
      ]
    }
  ],
  "icons": {
    "48": "icons/icon48.png"
  }
}