Examine source code of SendWhatsappMessageto...

{
  "manifest_version": 2,
  "name": "SendWhatsappMessageto...",
  "version": "1.1",
  "description": "Send WhatsApp messages directly to any number.",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "permissions": [
    "activeTab",
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": false
  },
  "browser_specific_settings": {
    "gecko": {
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "id": "{c48d7bc1-9edc-47bc-9ece-fa9e51b6b0eb}"
    }
  }
}