Unity3d lift movement down with keycode

Unity Engine
1

Hello
this code does so when I press the A key or the B key, the elevator stops upwards on the first or second floor. The question is how do I modify the code that when the elevator is on the second floor, for example, and I press the A key again to make the elevator go down to the first floor? Question two If I replace if (Input.GetKey (KeyCode.A)) {} with this if (Input.GetKeyUp (KeyCode.Keypad1)) {} so the code does not work. Why? Thank you for advice Sorry for the bad English. Here is the code

public GameObject lift;
private bool keyHHit=false;
private bool keyHHitB=false;

     void Update () {
   
 
     if (Input.GetKey(KeyCode.B)) {
                  keyHHit=true;
                     }
           if( keyHHit==true){
                 if(transform.localPosition.y >= 14.52){ 
                    transform.Translate(new Vector3(0, 0, 0) * 2 * Time.deltaTime, Space.Self);
                               }else{
             transform.Translate(new Vector3(0, 2, 0) * 2 * Time.deltaTime, Space.Self);
                     }
                   }
                  
                  
     if (Input.GetKey(KeyCode.A)) {
                  keyHHitB=true;                      
                     }
           if( keyHHitB==true){
                 if(transform.localPosition.y >= 8.52){ 
                 transform.Translate(new Vector3(0, 0, 0) * 2 * Time.deltaTime, Space.Self);
                             }else{
            transform.Translate(new Vector3(0, 2, 0) * 2 * Time.deltaTime, Space.Self);
            //transform.Translate(Vector3.up * 0.05f);
                     }
                     }              
             }
2

Have an array or list of vectors or transforms and then cycle through that list to move to the next point. Personally, I would use a coroutine and lerp from point to point or lerp from the current position to the next in the update method.