Hold to jump higher

I have the following code that I have written in order to make a character jump higher if the jump button is held down.

The character performs the initial jump fine but the statement around the button holding never gets triggered since Time.time is not greater than lastJumpTIme. Its obvious that I have gone wrong in my calculations somewhere, I just dont know where.

 private void HandleJumping() {
  
      if (grounded && ! crouching) {
          if (Input.GetButtonDown ("Jump")) {
              force = jumpForce;
              lastJumpTime = Time.time + 0.5f;
          }
      }
  
      if (lastJumpTime != 0f) {
          Debug.Log (Time.time.ToString () + " - " + lastJumpTime.ToString ());
      }
      
      if (Input.GetButton ("Jump") && force != 0f && Time.time > lastJumpTime) {
          //force += 100f;
          Debug.Log ("HIGH");
      }
  
      if (grounded) {
          lastJumpTime = 0f;
      }
  
      if (force != 0f) {
          rb2d.AddForce (new Vector2 (0f, force));
          force = 0f;
      }
  }