Webhook calling with an invalid HTTP request

I’ve created webhook app that is making Zoom to call my url: https://softalks.com/zoom/handler

The problem is that Zoom is invoking this endpont without even specifying an HTTP method, URI and protocol/version resulting in a BadRequest (HTTP 400 status code) response from my server

My server log:

#Fields: c-dns cs-method cs-uri sc-status
#Version: 2.0
#Software: Apache Tomcat/9.0.58 (Ubuntu)
90.162.212.170 POST /zoom/handler 204
3.235.82.171 null null 400

The first line references a simulated invocation from my own client.

The second one is the only Zoom footprint in my server logs and it appears each time a registered event is notified by Zoom to my server

The IP address 3.235.82.171 seems to be the Zoom address, where event notifications are fired from

I’ve tested also to log the x-H(protocol) field and is it has no value when called from Zoom (it was expected to get an " HTTP/1.1" or " HTTP/2.0" value instead as I get from any other HTTP invocation)

The log file format is based on this standard: Extended Log File Format

Thanks in advance