Audio from the eg25-GL 4g hat with a raspberry pi 4

Hi, I am trying to get audio from the eg25-GL 4g hat with a raspberry pi 4. I followed this guide Getting Started with the Raspberry Pi 4G LTE HAT | Seeed Studio Wiki

But I am still not getting any audio when making a call via minicom. I have the gpio pins connected as well as the usb data. Any ideas? Thx