how to make OnMouseDown() and OnMouseUp() work on ipad?

this is my code, it can work on unity 3D, but when i depoly it on ipad, it can not work. how to change it? help, thanks

function OnMouseDown() {
if (transform.position.y < 1.25) { // Only pick up coin if below this height
rigidbody.isKinematic = true;
clicked = true;
mouseCursor.gameObject.audio.Play();
var startPosition = transform.position;
var moveStartTime = Time.time;
raycastArea.active = true;

	// Raise coin up
	fromRotation = transform.rotation;
	while (transform.position.y < .5) {
		transform.position.y += Time.deltaTime * pickupSpeed;
		// Also move it to the exact position defined by the mouse click position over time
		// Otherwise there's a bit of a jump unless you click on the exact center of the coin
		transform.position.x = Mathf.Lerp(startPosition.x, CursorControl.handPos.x, (Time.time-moveStartTime) * pickupSpeed);
		transform.position.z = Mathf.Lerp(startPosition.z, CursorControl.handPos.z, (Time.time-moveStartTime) * pickupSpeed);
		yield;
	}
	// Get a starting reference for the rotation slerp, so (Time.time-startTime) starts out near 0
	startTime = Time.time;
	
	while (transform.position.y < 1.1) {
		transform.position.y += Time.deltaTime * pickupSpeed;
		transform.position.x = Mathf.Lerp(startPosition.x, CursorControl.handPos.x, (Time.time-moveStartTime) * pickupSpeed);
		transform.position.z = Mathf.Lerp(startPosition.z, CursorControl.handPos.z, (Time.time-moveStartTime) * pickupSpeed);
		yield;
	}
}

}

Short answer- You don’t.

Long answer- Instead you can use Input.GetTouch!