How to make player crouch smoothly, PLZ HELP !!!!

My bad, I rushed the code previously and did not think you'd like to just change the transform Y-Position. Here is a revised one, done with more effort. Enjoy yourself

  public bool isCrouched = false;
     public CharacterController controller;
     public float crouchDistance = 0.9f;
     public float crouchingSpeed = 0.7f;
     public bool isChangingPosition = false;
 
     // Start is called before the first frame update
     void Start()
     {
         controller = GetComponent<CharacterController>();
     }
 
     // Update is called once per frame
     void Update()
     {
         //True if Key Pressed and Not changing positions currently
         if (Input.GetKeyDown(KeyCode.C))
             StartCoroutine(Crouch());
     }
 
     private IEnumerator Crouch()
     {
         //True if we're already changing position, then end this function
         if (isChangingPosition)
             yield break;
 
         //Acknowledge that we are changing position so above criteria will keep out multiple calls
         isChangingPosition = true;
 
         //Get our Starting Height
         float StartingHeight = transform.position.y;
 
         //Find our End Height
         float EndHeight;
         if (isCrouched)
             EndHeight = StartingHeight + crouchDistance; //We are crouched, hence we are trying to stand up (Go Up / Increase)
         else
             EndHeight = StartingHeight - crouchDistance; //We are standing, hence we are trying to crouch (Go Down / Decrease)
 
         Debug.Log("E" + EndHeight);
 
         //Keep changing the Y Value until we reach the end height
         while (transform.position.y != EndHeight)
         {
             //Here we check what action we're doing (Standing/Crouching)
             //Then we move according to the action
             //And finally we check if we have reached the End
 
             if (isCrouched)
             {
                 //We are crouched, hence we are trying to stand up (Go Up / Increase)
                 transform.Translate(Vector3.up * crouchingSpeed * Time.deltaTime);
 
                 //True if we reached our goal
                 if (transform.position.y >= EndHeight)
                 {
                     //Make sure we are EXACTLY at the EndHeight
                     transform.position = new Vector3(transform.position.x, EndHeight, transform.position.z);
                     Debug.Log("COMPLETE!");
                 }
             }
             else
             {
                 //We are standing, hence we are trying to crouch (Go Down / Decrease)
                 transform.Translate(Vector3.down * crouchingSpeed * Time.deltaTime);
 
                 //True if we reached our goal
                 if (transform.position.y <= EndHeight)
                 {
                     //Make sure we are EXACTLY at the EndHeight
                     transform.position = new Vector3(transform.position.x, EndHeight, transform.position.z);
                     Debug.Log("COMPLETE!");
                 }
             }
             yield return null;
         }
 
         //We have reached the end!
 
         //Flip the Action as we have succeeded in changing now
         isCrouched = !isCrouched;
 
         //We're finished changing!
         isChangingPosition = false;
 
         yield return null;
     }