2018 Lenovo ThinkCentre M920X (RX560) [9th,8C,T] + GTX 1660 Ti @ 32Gbps-M2 (ADT-Link R43SG) + Win10 [dengke80622]
CPU i9-9900t, PCIe Configurations: 1x8+2x4
m.2 m key ssd 1tb @ pcie 3.0 x4
integrated GPU1 UHD630 on-chip
integrated GPU2 RX560 @ pcie 3.0 x8
OS: win10 pro for workstation x64 with lastest update
There's no trick on configuration, just set "AUTO" in BIOS, plug m2 connector into 2nd m-key slot on the motherboard.
Connect external GPU with a display and power on, even no restart required after installing Nvidia drivers.
Here's testing screenshots
Upload benchmark results, tested twice with external display