How to Move IK to the Touch Position

Hi, I have a 3d character in a 3d environment and I am trying to move the Two Bone IK Constraints > Target object to the "Touch Position" of the player so I can move and rotate them to avoid hitting some obstacles. The code I have so far is down below, but it is not working. Whenever I touch the screen, the target object snaps to the character and not moving anymore at all.

 if (Touchscreen.current.primaryTouch.press.isPressed)
             {
                 Vector3 touchPosition = Touchscreen.current.primaryTouch.position.ReadValue();
 
                 Vector3 worldPosition = mainCamera.ScreenToWorldPoint(touchPosition);
 
                 movementDirection = worldPosition - leftArmIK.transform.position;
 
                 leftArmIK.transform.position = new Vector3(movementDirection.x, movementDirection.y, movementDirection.z);
 
                 movementDirection.Normalize();
             }

I have been trying to solve this problem since yesterday, but couldn't find a solution on my own. So I'd be so greatful for any help or advice.