Hero not moving

using UnityEngine;

public class HeroScript : MonoBehaviour
{
    // Set my Speed. If There is no speed, you can't move.
    [SerializeField] private float memberSpeed = 10.0f;

    // I still don't know.
    private SpriteRenderer memberSpriteRenderer = null;

    // I STILL don't know. Rigid Body.
    private Rigidbody2D memberRigidBody = null; // I don't know, I'll tell you later.

    // Start is called before the first frame update
    void Start()
    {
        // Get the rigid body that we added in Unity.
        memberRigidBody = this.GetComponent<Rigidbody2D>();
    }

    // Update is called once per frame
    void Update()
    {
        // Which direction does the player want to go?
        // Assume the player doesn't want to move, so no direction.

        Vector3 localWhichDirection;
        localWhichDirection = Vector3.zero;

        if (Input.GetKey(KeyCode.LeftArrow))
        {
            // if the player presses the left cursor key, player should walk left.

            localWhichDirection = Vector3.left;
        }
        else
        if (Input.GetKey(KeyCode.RightArrow))
        {
            // if the player presses the right cursor key, player should walk right.

            localWhichDirection = Vector3.right;
        }

        if (Input.GetKey(KeyCode.UpArrow))
        {
            // if the player presses the up cursor key, player should walk up.

            localWhichDirection = Vector3.up;
        }
        else
       if (Input.GetKey(KeyCode.DownArrow))
        {
            // if the player presses the right cursor key, player should walk down.

            localWhichDirection = Vector3.down;
        }
    }
}