我开始了我的第一个游戏项目，我坚持我的破折号
我的破折号随机开始工作时，我按下破折号按钮（R），但它并不总是工作。我是新的游戏开发，并试图寻找解决方案-像固定更新或添加力量或转换。位置-但没有帮助。如果你有任何想法，你能帮助我吗？
我代码如下

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

public class PlayerMovement : MonoBehaviour
{
    private Rigidbody2D rb;
    private BoxCollider2D coll;
    private int jumpCount = 1;

    private bool canDash = true;
    private bool isDashing;

    [SerializeField] private LayerMask jumpableGround;
    
    // Start is called before the first frame update
    private void Start()
    {
        rb = GetComponent<Rigidbody2D>();
        coll = GetComponent<BoxCollider2D>();
    }

    // Update is called once per frame
    private void Update()
    {
        float dirX = Input.GetAxisRaw("Horizontal");
        rb.velocity = new Vector2(dirX * 7f, rb.velocity.y);

        if (Input.GetButtonDown("Jump") && jumpCount != 0)
        {
            rb.velocity = new Vector2(rb.velocity.x, 12f);
            jumpCount--; 
        }

        if (IsGrounded())
        {
            jumpCount = 1;
        }

        if(Input.GetKeyDown(KeyCode.R) && canDash)
        {
            _ = StartCoroutine(Dash());
            
        }
    }
    private bool IsGrounded()
    {
        return Physics2D.BoxCast(coll.bounds.center, coll.bounds.size, 0f, Vector2.down, .1f, jumpableGround);
    }

    private IEnumerator Dash()
    {
        canDash = false;
        float originalGravity = rb.gravityScale;
        rb.gravityScale = 0f;

        rb.velocity = new Vector2(rb.velocity.x, 0f);
        rb.AddForce(new Vector2(rb.velocity.x * 24f, 0f), ForceMode2D.Impulse);
        Debug.Log("something");

        rb.gravityScale = originalGravity;
        yield return new WaitForSeconds(0.1f);
        canDash = true;
    } 
}