Is there any way we can pass header in the body of create webhook API?

Since Adobe Sign validates the url passed in the body of create webhook API before creating the webhook by sending a GET request. The url which i am using expects 'Content-Type' header because of which url is not getting hit and i am getting "INVALID_WEBHOOK_URL". So is there any way we can pass header also in the body so that Adobe sign can use the header to call the url. Something like this 

{
"webhookUrlInfo": {"url": "{URL}",
                                   "header": "Content-Type:application/json"},
"webhookSubscriptionEvents": [
"AGREEMENT_ACTION_COMPLETED"
],
"scope": "ACCOUNT",
"name": "Test",
"state": "ACTIVE"
}