Its a mega2560 board you need to enable #define SERIAL_PORT 0 And #define BAUDRATE 115200
UART 0 is connected to a usb to serial chip. Normally a ch340 chip. If you using windows you need to install drivers for the OS to see port
UART 0 is connected to a usb to serial chip. Normally a ch340 chip. If you using windows you need to install drivers for the OS to see port