Convert C into Arduino Uno 3

I attached the motor with Motor Driver and Uno 3. Can you please complete the code below ? I want to add the starting lines. Please define pins.

void setup() {
  
  //Setup Channel A
  pinMode(12, OUTPUT); //Initiates Motor Channel A pin
  pinMode(9, OUTPUT); //Initiates Brake Channel A pin
  
}

void loop(){
  
  //forward @ full speed
  digitalWrite(12, HIGH); //Establishes forward direction of Channel A
  digitalWrite(9, LOW);   //Disengage the Brake for Channel A
  analogWrite(3, 255);   //Spins the motor on Channel A at full speed
  
  delay(3000);
  
  digitalWrite(9, HIGH); //Eengage the Brake for Channel A

  delay(1000);
  
  //backward @ half speed
  digitalWrite(12, LOW); //Establishes backward direction of Channel A
  digitalWrite(9, LOW);   //Disengage the Brake for Channel A
  analogWrite(3, 123);   //Spins the motor on Channel A at half speed
  
  delay(3000);
  
  digitalWrite(9, HIGH); //Eengage the Brake for Channel A
  
  delay(1000);
  
}

I connected GND to UNO GND
DIR to pin 12
PWM to pin 3 of UNo 3.
Break to pin 8