I need help with this script

Hello .
I am new on Unity. I want to make a third game and downloaded on assest store about Basic Motions FREE and import on Unity. How can I Rotation with the keyboard the character on C# but it doesn’t work.
How can i solve that Problem ?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class PlayerControl : MonoBehaviour
{
// Start is called before the first frame update
private Rigidbody player;
public float speed;
public float jump;
private bool isGrounded = true;
public float gravityScale;

void Start()
{
    player = GetComponent<Rigidbody>();
    
}

// Update is called once per frame
void Update()
{

    Vector3  dir = new Vector3(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
    
    player.AddRelativeForce(dir * speed, ForceMode.Impulse);

    player.AddForce(Physics.gravity * (gravityScale - 1)* player.mass);
    player.velocity = Vector3.zero;

   
    

    if (Input.GetButtonDown("Jump")&& isGrounded)
    {
        player.AddForce(0, player.transform.position.y + jump, 0,ForceMode.Impulse);

        isGrounded = false;
        

    }


    
}
private void OnCollisionEnter(Collision collision)
{
    if(collision.gameObject.tag == "Boden")
    {
        isGrounded = true;
    }

}

}

You have no code that drives the rotation of your PlayerControl. You could use the mouse to rotate your player.

    private void Update()
    {
        float yaw = Input.GetAxis("Mouse X");
        transform.Rotate(0, speed * yaw * Time.deltaTime, 0, Space.World);
    }