Can't connect online

[Jbtn]

I am trying to get my Dreamcast online. I live in Japan, so I'm trying to build with locally available parts. It's not working.

Error in XDP:
"There is no answer at this telephone number. Check your ISP Phone #."

Setup:
Raspberry Pi 3B
Latest Dream Pi software (wifi settings added)
AGPTek modem with Conexant (both lights turn on, https://www.amazon.co.jp/dp/B008RZTJC0 )
Line Voltage Inducer (following the wiring instructions from Dream Pi tutorial, with soldering and 330ohm resistor)
JP Dreamcast
XDP browser (following Dream Pi setup recommendations)

Troubleshooting so far:
Built 2 completely separate LVI using different RJ11 brands
Confirmed connections on LVI red wire with multimeter

What could be the issue?

How can I confirm the Dream Pi and USB modem are working together?

How can I confirm the Dreamcast modem is working? Is there any way to hear the tone and dial up?

The modem has LINE and PHONE ports. Which should I connect to Dreamcast?

Thank you.

[Nico0020]

I see you set up the wifi, have you tried connected with an all wired connection and see if that works first?

[Jbtn]

Hi. Thank you for replying.
I tried direct LAN wire and Wifi both.

[Xiden]

Hi. Thank you for replying.
I tried direct LAN wire and Wifi both.

Hey there do you have discord? PM user scrivani on there or join the dctalk discord and we can help you better there