So you want to install Win 11. set bios at UEFI mode, no legacy support. prepare a Win 11 installation media usb flash drive using MS media creation tool.  Create Windows 11 Installation Media“If you want to perform a reinstall or clean install of Windows 11 on a new or used PC, use this option to download the media creation tool to make a bootable USB or DVD.” insert usb drive in pc before power on tap F12 repeatedly immediately after power on you should see UEFI: USB mass storage device show up on screen.  Use arrow to move to that option and proceed to install (clean install via advanced mode recommended)
XPS 8930 boots windows 10 in legacy mode. I need UEFI mode and GPT formatted disks for windows 11. If I change the bios to UEFI the only boot option is ONBOARD NIC IPV4 and IPV6 I've tried adding a clean GPT disk on one SATA cable . but nothing shows up. I've tried a USB drive with linux but that doesn't show up either even with Enable USB boot support enabled and Attempt Legacy boot enabled I get just a blank screen if I do try to boot with the USB stick plugged and this setup. It worked fine with legacy mode. I have updated all drivers and firmware from the Dell support site.
XPS 8930, UEFI boot does not show any HDD