Smooth movement when input is pressed

Well, I’m beginner in this and my question is how to move an object to it’s right smoothly when player pressed right?
I’ve tried this, but I’ve to keep pressing the button. I want only one push button and the object move until the destination.

    var smoothTime = 0.3;
    var isMoov = false;
    private var velocity = Vector3.zero;
    
    function Update () {
		if(Input.GetButton("Horizontal")){
			var in_direction : int = Input.GetAxis("Horizontal") < 0 ? -1 : 1;
			if(in_direction == 1){			
				
        		var targetPosition : Vector3 = Vector3(25, 25, 25);                       		
        		transform.position = Vector3.SmoothDamp(transform.position, targetPosition,
                                     velocity, smoothTime);
			}			
		}	
    }

My knowledge of coding is quite limited but try changing Vector3.SmoothDamp to Mathf.SmoothDamp.

If that doesn’t work then I suggest going to youtube and looking at Eteeski tutorials FPS1.3,1.4 and 1.6. They are first person tutorials and he explains quite well the code and how it works.
The only thing is you will have to do is adjust the code yourself so it works for your game.

Hope this helps.
Peace!