The range for the duty cycle is 0 (always low) to 1024 (always high). If you want pulses then 1 is the shortest high going pulse, and 1023 is the shortest low-going pulse. 512 is a 50% square wave.
Unfortunately the pwm(A0, 732, 256); didn’t solve my problem. I want pin A0 on the XIAO SAM232D to output a pwm, not an analog voltage.