How do you move a character using a slider?

I trying to move a simple character using a slider but with what i have now I can move it using the keys and all forward momentum is automatic.

When the section for the slider is active it moves the player forward. as much as the slider is set for.
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here is the code so far:
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public class PlayerMotor : MonoBehaviour {

private CharacterController charController;
private Vector3 moveVector;

public float forwardSpeed = 5.0f;
public float leftRightSpeed = 5.0f;

public GameObject Player;

// Start is called before the first frame update
public void Start()
{
    charController = GetComponent<CharacterController>();
}

// Update is called once per frame
public void Update(float leftRightSpeed) //addition
{
    MovePlayer();

}

// This moves the player side to side using the arrow keys
public void MovePlayer() //addtion
{
    moveVector = Vector3.zero;

    moveVector.x = Input.GetAxisRaw("Horizontal") * leftRightSpeed;  //left-right

    moveVector.z = forwardSpeed;  //forward

    charController.Move(moveVector * Time.deltaTime);
}

// This moves the play with the slider. it's meant to be side to side but it moves it forwards
public void MovePlayer() //addtion
{
    Vector3 pos = Player.transform.position; //addtion
    pos.x = leftRightSpeed; //addtion
    Player.transform.position = pos; //addtion
    Debug.Log("moving sideways");

    moveVector.z = forwardSpeed;  //forward
    Debug.Log("moving forward");

    charController.Move(moveVector * Time.deltaTime);
}

}

Any suggestions as to how to resolve this?

using ui slider?
Slider slider;
set in hierarchy value -1 ; 1

and if slider.value < 0 then move player left, and > 0 to right