Manipulating accelerometer to get the right position with the viw

Hi , im trying to learn how to work with accelerometer but i have a few questions regarding it

I have this screen, and the red ball will be the one moving

this is the code im using:

 public class Done_PlayerController : MonoBehaviour{
 public float speed;
 public float tilt;
 public Done_Boundary boundary;
 void FixedUpdate ()
 {
 void FixedUpdate ()
     {
         float moveHorizontal = Input.acceleration.x;
             //Input.GetAxis ("Horizontal");
         float moveVertical =  (Input.acceleration.z); 
         Vector3 movement = new Vector3 (moveHorizontal,moveVertical,0.0f );
         rigidbody.velocity = movement * speed;
         
         rigidbody.position = new Vector3
          (Mathf.Clamp (rigidbody.position.x, boundary.xMin, boundary.xMax), 
           Mathf.Clamp (rigidbody.position.y, boundary.yMin, boundary.yMax), 
           0.0f
         );
         rigidbody.rotation = Quaternion.Euler (0.0f, 0.0f, rigidbody.velocity.x * >-tilt);
     }
 }
 

do i have any prob? tried all afternoon but nothing