ASUS DSL-AC56U modem wizard is only for ADSL connection.
If you want to use ASUS DSL-AC56U modem for NBN with FTTP (fibre to the premises), then go to WAN section then on Transfer Mode select Ethernet WAN.
Make sure your network cable is connected on UNI-D1 (or active UNI-D port) back to the E-WAN port of the ASUS DSL-AC56U modem.
