How to make a animation play when I press a key

Hey im trying to make a walking animation play when i press w,a,s,d (for a top down 2d game)

I have been looking around for a while and i could not fund anything.

Here’s my code (some of it is pointless because I did not delete the other ways I tried)

using UnityEngine;
using System.Collections;

public class PlayerController2D : MonoBehaviour
{

    public int moveSpeed;
    public int jumpHeight;
    public int Crouch;

    public Transform groundPoint;
    public float radius;
    public LayerMask groundMask;

    public float speed;
    public bool animation_bool;

    Animator anim;

    bool isGrounded;
    Rigidbody2D rb2D;

    


    void Start()
    {
        rb2D = GetComponent<Rigidbody2D>();
        anim = GetComponent<Animator>();
    }


    void Update()
    {
        Vector2 moveDir = new Vector2(Input.GetAxisRaw("Horizontal") * moveSpeed, rb2D.velocity.y);
        rb2D.velocity = moveDir;



        isGrounded = Physics2D.OverlapCircle(groundPoint.position, radius, groundMask);

        anim.SetFloat("speed", Mathf.Abs(Input.GetAxis("Horizontal")));



        if (Input.GetAxisRaw("Horizontal") == 1)
        {
            transform.localScale = new Vector3(1, 1, 1);
        }
        else if (Input.GetAxisRaw("Horizontal") == -1)
        {
            transform.localScale = new Vector3(-1, 1, 1);
        }
        GetComponent<ConstantForce>().enabled = false;
        
        if (Input.GetKeyDown(KeyCode.Space) && isGrounded)
        {
            rb2D.AddForce(new Vector2(0, jumpHeight));
        }
        if (Input.GetKeyDown(KeyCode.W))

            GetComponent<Animator>().SetBool("Walking up", true);

    }
        }

u can try to use 2d blend tree animation