Interactions endpoint URL with ngrok

[slingercode]

Similar issue closed without a solution.

Trying to add a URL from ngrok on the interactions endpoint URL of the app configuration, there is an error that refuses to save the data even when the connection is successful.

{
    "code": 50035,
    "errors": {
        "interactions_endpoint_url": {
            "_errors": [
                {
                    "code": "APPLICATION_INTERACTIONS_ENDPOINT_URL_INVALID",
                    "message": "The specified interactions endpoint URL could not be verified."
                }
            ]
        }
    },
    "message": "Invalid Form Body"
}

[slingercode]

Solved.

The reason of the error is because the API does not solve a PING event. After updating the code with this validation works fine

Here is the section of the docs that explains this.