Hi @Ashok Kumar
I still get the same error after editing both PythonRuntimeLibrary and PyhtonRuntimeLibraryVersion. 

He's the situtation:
Windows 11 x64
Installed 2024.1 first, then upgraded to 2024.3 developer preview version
C:\InterSystems\IRIS\lib\python\ folder is present with 9 files. (From the original 2024.1 installation) 
I then installed Python 3.13 and let the installer add the system path variable
set PythonRuntimeLibrary - C:\Program Files\Python313\python3.dll (also tried C:\Program Files\Python313\python313.dll)
PythonRuntimeLibraryVersion - 3.13

I tried renaming the lib\python\ folder to see if anything changed but no luck
\mgr\python is empty

when running python from windows itself, it works as expected

Restarted both IRIS and the whole machine couple of times while testing. 

Any ideas? 
Thanks

This text mentions that requests will be treated as concurrent users with multiple connections. This would be totally fine, if I managed to send the SessionID Cookie so the system recognizes multiple requests coming from the same user. 

However, each request is treated as a new user, as I am unable to send the cookie with XMLHttpRequests whereas the CSP.Broker Method is able to send the Cookie.

I'm a little confused now... 

When talking about a normal external Apache server, you would only need to add a couple of Cypher Suite Keys and change the protocol version. 
Intersystems Webgate also uses Apache Web Server as far as I can see in the Webgate Management. 
How come I need to add python code to my application in order for a browser to send its request via HTTP/2? 

I'm not really that well trained in server management but I feel like there is something I'm missing here. 

Why is the application responsible for the request instead of the apache server?