Create Webhook Header

curl --request POST \
  --url https://sandbox-api.violet.io/v1/events/webhooks/{webhook_id}/headers \
  --header 'Content-Type: application/json' \
  --data '{
  "app_id": 123,
  "webhook_id": 123,
  "key": "<string>",
  "value": "<string>"
}'

{
  "id": 123,
  "app_id": 123,
  "webhook_id": 123,
  "key": "<string>",
  "value": "<string>",
  "date_created": "2023-11-07T05:31:56Z",
  "date_last_modified": "2023-11-07T05:31:56Z"
}