Motor Shield v2.0 Help! Frequency/ controlling PWM and Frequ

I am trying to control a dc motor using an Uno along with the Motor Shield v2 and I’m hoping someone can help because I can not seem to figure this out.

Ideally I would be able to control a single DC motor that only needs to move in one direction.

The PWM should be set at 15khz but Im not sure I have that option so I believe I can get away using timer 1 available on pins 9/10 with TCCR1B = TCCR1B & 0b11111000 | 0x01; (~31khz)

The speed/duty cycle precisely controlled by a constantly varying 5k potentiometer/ throttle.

The issue Im having is controlling the Uno’s outputted PWM frequency and having the motor shield output the same. No matter what changes Ive made, I always seem to get the default frequencies on the Motor Shield side.

How can I control the Motor Shields outputted frequency.

Thank you in advance for the help, its much appreciated!

#include “MotorDriver.h”

const int POT_PIN = A0;
int motorSpeed = 0;
int potVal = 0;
int pinI1=8;//define I1 interface
int pinI2=11;//define I2 interface
int speedpinA=9;//enable motor A

void setup()
TCCR1B = TCCR1B & 0b11111000 | 0x01;


void loop()
potVal = analogRead(POT_PIN);
motorSpeed = map(potVal, 0, 1023, 0, 255);

analogWrite(speedpinA, motorSpeed);
digitalWrite(pinI2,LOW);//turn DC Motor A move anticlockwise