Sonoff Zigbee 3.0 USB Dongle Plus nowhere to find in HAOS

I’m a complete newbie to Home Assistant and am running into the problem that the Sonoff Zigbee 3.0 USB Dongle Plus isn’t visible/findable in HAOS.

I recently bought a used Intel NUC 7i5dne with 4GB of RAM and a 256GB SSD. I installed Proxmox and HAOS on it. The installation went smoothly. Then I installed the Mosquito Broker MQTT add-on and the Zigbee2MQTT add-on. I also bought a Sonoff Zigbee 3.0 USB Dongle Plus and flashed it to the latest firmware via the Sonoff website (on my Win 11 Pro PC). Flashing the dongle in a 3.0 USB port didn’t work, but in a 2.0 USB port, flashing worked flawlessly. In Win 11 Pro, the dongle is correctly recognized in both USB 2.0 and USB 3.0 ports. So far so good.

Now the problem:
In HAOS under Devices and Services, the Sonoff dongle isn’t visible in either ZHA or Zigbee2MQTT, and it’s not visible when I point to the serial port (e.g., /dev/ttyS0) in ZHA. It also doesn’t matter whether I plug the dongle directly into the NUC or use a USB extension cable.

I read somewhere that inserting the dongle into a USB 3.0 port sometimes causes problems, but the Intel NUC 7i5dne only has four USB 3.0 ports.

What am I missing or doing wrong? Who can help me/have the answer?

Have you added it to the virtual machine?

Meanwhile the problem is solved.

I’ve found below Internet site and followed it step-by-step.

Proxmox USB Passthrough to Home Assistant VM - SmartHomeScene The USB Vendor/Device ID Method