Examine source code of WhatsApp Link Creator

{
  "manifest_version": 2,
  "name": "WhatsApp Link Creator",
  "version": "1.0",
  "description": "Create WhatsApp link from selected text",
  "permissions": [
    "contextMenus",
    "activeTab"
  ],
  "icons": {
    "48": "wa.png"
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{2d321830-606e-4bce-af30-e00d2d0a454c}"
    }
  }
}