You probably need to extend from their images as Notebook/container management is wired into the Portal.
I was able to get this to work but it looks running Linux containers (for CUDA support) on Windows host is not supported after 11.3 (due to Docker Desktop not being supported anymore) - https://enterprise.arcgis.com/en/notebook/11.4/administer/windows/what-s-new-in-arcgis-notebook-serv....