You cannot access the microRendu setup unless it is on the network, which it is not because it is plugged into the DAC. The microRendu requires it’s IP address to be provided by DHCP which is done by, typically, your router. So the microRendu needs to be plugged into the network. As stated in another thread about this very topic, the manufacturer said this directly:
While you might have read of people setting the microRendu in a direct connection, the methods used to actually get it working and circumnavigating the DHCP requirement are involved, require specific equipment, specific setup and has the potential to mess up your entire network if you set things wrong.