From looking at the source code of the proxy what I’ve found is that Osyris is using an express server to set up routing on his hosting. This basically means that you can set up endpoints at the end of your domain that you can send GET or POST requests to. In this case, he has it set up like so:
"/api/webhooks/:hookId/:hookToken" which is listening for POST requests with the required fields hookId and hookToken in the URL after
/api/webhooks/. This means that you could get your own hosting or set it up on Docker as explained in the main post, and use it to send requests.
So considering how the routing is set above, if your web app was located at the web address ‘aspheric.something.com’ you could send POST requests to, for example,
Hope this helped.