Callback handler for Custom App

Hi Community!
Recently started working on building a custom app on frappe to be used with erpnext. I would like to receive JSON from a POST that has the following data params.

"national_id": "12345",
"callback_url": ""

The API sends the Callback response to the callback URL but I do not know how to receive the json data sent to the callback URL into the custom app. The data is to be parsed onto a form in a doctype.

Would appreciate any assistance on this :slight_smile: