Dash for 2d game

hi im trying to make a game and am currently struggling with the dash mechanic, and really need help.

thanks in advance!

here is my code so far:

 private Rigidbody2D rb;
 public float speed;
 public float jumpForce;
 private float moveInput;

 private bool isGrounded;
 public Transform feetPos;
 public float checkRadius;
 public LayerMask whatIsGround;

 private float jumpTimeCounter;
 public float jumpTime;
 private bool isJumping;
 public float dashSpeed = 100f;
 private float dashTime;
 public float startDashTime;
 private int direction;



 // private Vector2 lastMoveDir;


 void Start(){
     rb = GetComponent<Rigidbody2D>();
     dashTime = startDashTime;
 }
 
 void FixedUpdate(){
     moveInput = Input.GetAxisRaw("Horizontal");
     rb.velocity = new Vector2(moveInput * speed, rb.velocity.y);
     // float x = Input.GetAxis("Horizontal");
     // float y = Input.GetAxis("Vertical");
     
     // Vector2 dir = new Vector2(x, y);
 }

 void Update(){
     
     float xRaw = Input.GetAxis("Horizontal");
     float yRaw = Input.GetAxis("Vertical");
     isGrounded = Physics2D.OverlapCircle(feetPos.position, checkRadius, whatIsGround);

         if(isGrounded == true && Input.GetKeyDown(KeyCode.W)){
             isJumping = true;
             jumpTimeCounter = jumpTime;
             rb.velocity = Vector2.up * jumpForce;
         }

         if(Input.GetKey(KeyCode.W) && isJumping == true){

             if(jumpTimeCounter > 0){
                 rb.velocity = Vector2.up * jumpForce;
                 jumpTimeCounter -= Time.deltaTime;

             }else{
                 isJumping = false;
             }
             
         }

         if(Input.GetKeyUp(KeyCode.W)){
             isJumping = false;
         }
     if(Input.GetKeyDown(KeyCode.Space)){
         if (direction == 0){
             if (Input.GetKeyDown(KeyCode.A)){
                 direction = 1;
                 Debug.Log("left");
             }else if (Input.GetKeyDown(KeyCode.D)){
                 direction = 2;
                 Debug.Log("right");
             }
         }else{
             if (dashTime <= 0){
                 direction = 0;
                 dashTime = startDashTime;
                 rb.velocity = Vector2.zero;
             }else{
                 dashTime -= Time.deltaTime;

                 if(direction == 1){
                     rb.velocity = Vector2.left * dashSpeed;
                 } else if(direction == 2){
                     rb.velocity = Vector2.right * dashSpeed;
                 }
             }

         }

     }
     
 }
 

}

my movement is fine, but the dash...smh it just wont work. btw, I'm going for a celeste feel to this movement. thanks!