Hi @dwang11 the ARRIS device is only the cable modem that interfaces the incoming HFC co-axial cable to the WAN connection on a separate router, it does'nt have any Wi-Fi functionality. The Wi-Fi password for your router will be printed on a sticker either on the rear or underside of the unit.
Welcome to the Community!
The Wi-Fi name & password is indicated on the sticker at the back of your TP-Link router.
It should look like this:
For reference, you may also visit this article on how to set up your NBN HFC connection:
Should you wish to change your W-Fi name and password, you may follow the steps from this article:
For additional assistance, please don't hesitate to reach out to us again.