convert a keyboard input to a TouchPhase.moved

Hi everyone! I've made a runner game for android where the player is a ball that runs over a road and can move on the X axis with touch. I've used this code for touch inputs

         float moveHorizontal = Input.GetAxis("Horizontal");
         transform.position = Vector3.Lerp(gameObject.transform.position, new 
         Vector3(Mathf.Clamp(gameObject.transform.position.x + moveHorizontal, -3.0f, 3.0f), 
         gameObject.transform.position.y, gameObject.transform.position.z), directionSpeed *  
         Time.deltaTime);

         Vector2 touch = Camera.main.ScreenToWorldPoint(Input.mousePosition + new Vector3(0, 0, 10f));
 
 
         if (Input.touchCount > 0 && Input.GetTouch(0).phase == TouchPhase.Moved)
             transform.position = Vector3.Lerp(gameObject.transform.position, new Vector3(Mathf.Clamp(touch.x, -3.0f, 3.0f), gameObject.transform.position.y, gameObject.transform.position.z), directionSpeed * Time.deltaTime);
 
 

because I want the ball to stay only on the road and move only horizontally.

Now, I'd need to know if there is a way to convert a keyboard input as a touch input. I mean, if I press a keyboard button, the ball slides on the left, and the same for right movement...

I need this because I've installed the app on a tv box with android installed (not an android TV box), and if I try to use a bluetooth keyboard with a touchpad, I only see the mouse pointer appearing and cannot move the ball... Any hint?