I tried to connect using a USB-C - USB regular to gateway and apparently I couldn’t see it. The file you sent mention lora, is this a new version of the firmware? How can I install it?
As a purpose of flashing firmware image in gateway and setting it to Maskrom mode, you could connect to it with USB type-C port. And if you want to log in gateway, you could use the Ethernet connection and ssh tool.
DSGW-210B series gateway have LoRaWAN module, and there’s a specific firmware for this gateway version.