Hi,
What is the light status of the Archer VR900?
Do you connect the telephone line to the DSL port or connect the ethernet cable to the LAN4/WAN port?
If it is the DSL port, the operation mode should be DSL modem router mode, vice versa.
If there is no internet access, it is suggested to contact TPG to confirm the configuration parameters, including the username and password and the VLAN ID.
Meanwhile, you can leave VLAN ID as empty to give it a go.
Any updates, please let us know.
Have a nice day.