Using pushbutton to make Stepper motor rotate 90 degrees
I edtied few things in your code. I am not sure if LOW value is correct, so I replaced it with HIGH. Second thing is timing. I removed all delay() functions instead of it you can see usage of millis(). That's for handling interval between button press and button release - second part of if will check if last time of button press is bigger than 200ms, if yes, move stepper. Last things is stepping. You can see here stepper.step(STEPS/4);. STEPS is variable which you declared on the top of code. It's called steps per revolution, one revolution is 360° so 90° will be STEPS/4.

Here is the code, read it and test it:

#include &lt;Stepper.h&gt;;


// pushbutton pin
const int buttonPin = 2;

const int STEPS = 32;
Stepper stepper(STEPS, 8, 10, 9, 11);


//create a variable to store a counter and set it to 0
int counter = 0;

unsigned long last_button_time = 0;   //for aving last millis 



void setup(){
  pinMode(buttonPin, INPUT);
  stepper.setSpeed(1000)
}


void loop(){
  bool buttonState;   // local variable to hold the pushbutton states

  //read the digital state of buttonPin with digitalRead() function and store the           //value in buttonState variable
  buttonState = digitalRead(buttonPin);

  //if the button is pressed increment counter and wait a tiny bit to give us some          //time to release the button
  if(buttonState == HIGH &amp;&amp; millis() - last_button_time &gt; 200){ // light the LED  
    last_button_time = millis();
    counter++;
    stepper.step(STEPS/4);    //90° degrees 
  }
}