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;
     }
 }

}