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

public class MotionControl : MonoBehaviour
{
    public float speed = 3f;  //定义一个速度

    // Start is called before the first frame update
    void Start()
    {
        
    }

    // Update is called once per frame
    void Update()
    {
        //控制物体移动
        float horizontal = Input.GetAxis("Horizontal");
        float vertical = Input.GetAxis("Vertical");

        transform.Translate(new Vector3(horizontal, 0, vertical) * speed * Time.deltaTime);
    }
}

Edit - Project Settings - Input Manager

它的名字是 Horizontal ，控制左右的分别是 a 和 d 键

下面还有一个 Vertical，是控制前后的