Examine source code of Flash Cardon

{
  "manifest_version": 3,
  "name": "Flash Cardon",
  "description": "Language learning aid",
  "version": "1.0.3",
  "icons": {
    "16": "icon_16.png",
    "19": "icon_19.png",
    "48": "icon_48.png",
    "128": "icon_128.png"
  },
  "action": {
    "default_icon": {
      "19": "icon_19.png"
    },
    "default_area": "navbar"
  },
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "permissions": [
    "activeTab",
    "storage",
    "contextMenus",
    "unlimitedStorage",
    "scripting"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{c281be50-fe1d-4239-a383-b236b3369280}",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "strict_min_version": "58.0"
    }
  }
}