Have you connected the onboard graphics to a monitor? If you have, in device manager go to VIEW> SHOW HIDDEN DEVICES and see if it is listed.
I have an Nvidia 3060ti installed and the encoders are quite fast but they also create massive file sizes which is not ideal for my application. Running Bios 1.7 and I have enabled the intel Multi option in bios as well as installed the Intel driver from the Dell support page. Device manager does not see an additional graphics device so my ability to use the Quick sync encoders are grayed out in all of my software options. Did I miss a step when trying to enable this?
XPS 8950, enabling Intel UHD graphics