Examine source code of Key Speed

{
  "manifest_version": 2,
  "name": "Extension",
  "version": "3.1.0",
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": [
          "technicalAndInteraction"
        ]
      },
      "strict_min_version": "109.0",
      "id": "{ea642589-3a86-4b86-8248-f875601b4f3d}"
    }
  },
  "background": {
    "scripts": [
      "assets/js/home/background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_popup": "start.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "permissions": [
    "clipboardRead"
  ],
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  }
}