Behaviour.cs

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

public class Behaviour : MonoBehaviour
{
    public float speed;
    public float jumpForce;
    private float moveInput;

    private Rigidbody2D rb;

    private bool facingRight = true;

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

    public int extraJumps;
    public int extraJumpsValue;

    //for transition
    public Animator animator;

    // Start is called before the first frame update
    void Start()
    {
        extraJumps = extraJumpsValue;
        rb = GetComponent<Rigidbody2D>();    
    }

    // Update is called once per frame
    void FixedUpdate()
    {
        isGrounded = Physics2D.OverlapCircle(groundCheck.position, checkRadius, whatIsGround);
        moveInput = Input.GetAxis("Horizontal");
        rb.velocity = new Vector2(moveInput * speed, rb.velocity.y);

        if (facingRight == false && moveInput > 0)
        {
            Flip();
        }
        else if(facingRight == true && moveInput < 0)
        {
            Flip();
        }
    }

    void Update()
    {
        animator.SetFloat("Speed", Mathf.Abs(moveInput * speed));
        if(isGrounded == true)
        {
            extraJumps = extraJumpsValue;
            animator.SetBool("IsJumping", false);
        }

        if(Input.GetKeyDown(KeyCode.UpArrow) && extraJumps > 0)
        {
            animator.SetBool("IsJumping", true);
            rb.velocity = Vector2.up * jumpForce;
            extraJumps--;
        }
        else if(Input.GetKeyDown(KeyCode.UpArrow) && extraJumps == 0 && isGrounded == true)
        {
            animator.SetBool("IsJumping", true);
            rb.velocity = Vector2.up * jumpForce;
        }
    }

    void Flip()
    {
        facingRight = !facingRight;
        Vector3 Scaler = transform.localScale;
        Scaler.x *= -1;
        transform.localScale = Scaler;
    }
}