can you say what this means?
the driver and motor you described is a dc motor driver, so the motor does not need pwm… the power and speed is regulated by voltage and power applied to the motor
The example source code is here
I would recomend placing Int1 on pin 1 and int 2 on pin 2
are you using Arduino IDE with Seeed Studio unit selected?
I am assuming you are not, and therefore you are defining the incorrect pins in the code… because Physical Pin 1&2 on the XIAO is not necessarily the GPIO pin of the chip
https://files.seeedstudio.com/wiki/Seeeduino-XIAO/res/XIAO-SAMD21-pinout_sheet.xlsx