RM500U-CNV: How to send AT commands over ethernet

I’ve got an RM500U-CNV in this external case: https://www.waveshare.com/wiki/5G_M.2_TO_Gigabit_ETH. Host is a Debian Linux 12 PC.

I can connect via USB, and Ethernet does also work. However, I don’t know how to send AT commands via Ethernet. Right now, I still need to have USB connected in order to send AT+CPIN=1234 and AT+QNETDEVCTL=1,1,1 for Internet access. How do I do this over Ethernet. My desire for Ethernet is to use a long cable between modem and PC.

Thanks Frank

Dear @fckruegel_opto
Please follow the steps to try:
AT+QCFG=“nat”,1
AT+QCFG=“eth_at”,1
Restart, then using Network Debugging Assistant to Send and Receive AT.