Want to use frequency 920 MHz korea. Need a sketch that works with Dragino LoRa Shield & Arduino Uno

I have dragino lora shield and arduino Uno with me. I wanted to use frequency band of South korea 920 Mhz.

I want to select Korea frequency 920 to 923 MHz for my board lora dragino shield. In ttn-otaa example where can i select korea frequency. Please guide