DSGW-010 Setting to use lte connection

I have SUM card for the device and would like to test connectivity. It’s clear how to insert the physical card by opening the device. But can you clarify what exact setting I have to fill in so that I can use the LTE connection?

Firstly, you need to power off your device and then insert the SIM card, secondly, please log in to your gateway and fill in the APN settings on the Luci page. It should locate on the Internet setting page. Finally, power on your gateway without the WAN port plugged in, the gateway should automatically turn on the LTE by itself.