How to send an SMS with XBEE3

Newbie developer here using XBEE3 LTE-M/NB-IoT to try to send SMS. Need guidance on how to configure modem in API mode 1 to send SMS. I’m using the XCTU currently to explore device configurations before porting it to our own hardware. I was able to follow the start-up example to get connectivity and test the loop-back server. I’m unable to send an SMS however. Looking for a minimum configuration setup to send/receive SMS in API1.