Can't get Push Channel to work

Hi guys

I'm new to the SAP world and I wanted to try out the Push Channels in my SAPUI5 application. I followed this tutorial: ABAP Channels Part 1: WebSocket Communication Using ABAP Push Channels

I created the Push Channel and generated the class and service as described in the tutorial. I activated all the functions, the class and the push channel.

Here is how this looks like in SE80:

And here is the class with the functions implemented like in the tutorial:

I tried to use the channel in my SAPUI5 app like this:

jQuery.sap.require("sap.ui.core.ws.WebSocket");

var webSocket = new sap.ui.core.ws.WebSocket("ws://192.168.36.12:8000/sap/bc/apc/sap/zui5_eval_push_notifications");

I also tried "wss" instead of "ws" but that didn't work either.

Problem is, I get an error 500 from the server.

What could I have missed here? I went through a lot of additional tutorials but I couldn't find anything that worked.

Thank you so much :-)