Header :
Content-type: application/json
Authorization: Bearer my_auth_token

{
"id":"An ID generated",
"type":"web_hook",
"address":"my callback address",
}

{
 "error": {
  "errors": [
   {
    "domain": "global",
    "reason": "required",
    "message": "Required parameter: pageToken",
    "locationType": "parameter",
    "location": "pageToken"
   }
  ],
  "code": 400,
  "message": "Required parameter: pageToken"
 }
}