Nvidia prime and using external monitor with intel gpu

So I want to run an external monitor on my 2019 pro while using the intel graphics. I am running ubuntu 20.04.

The HDMI port and thunderbolt port work for me while I am using the nvidia GPU. But job I do means I need to be able to use an external monitor without nvidia.

I have seen this rumour online that the HDMI is only connected to the nvidia but the thunderbolt should work for the intel. I can't get either to work.

The weird thing is my old rb 14 inch was able to output via HDMI using the intel. So its weird they changed this ??

Does anyone know where that rumor came from ?