I have checked your NBN-FTTP 100/40 service and can see the NBN-NTD looks ok.
You should make sure your mdoem is plugged into the UNI-D 1 port, and a network cable from there into the WAN port of your modem.
Is it a TPG supplied modem? What model is it?
Ok..i posted a guide in my last post.
If there is a solid WAN light on the modem that is a good start. t may need to have your TPG Username/Password entered into the modem for authentication.
If there see a setting for VLAN, make sure it is set for VLAN 2.
A factory reset on the modem may help first.
You can confirm you UN/PW by logging into your account.
One last check, are you sure that network cable is plugged in to the BLUE WAN port, and not 1 of the 4 LAN ports?