My bolt isn't respawning in game Its driving me crazy i have been at it for 2 days !!

console
error is

ArgumentException: input button fire1 is not setup To change setting s use edit -> Input PlayerController.update() (at Assets/Scripts/PlayerController.Cs:24)

and thank i'm new to development i'm still learning this enviroment do u have write var for button input as well is that what that means?

using UnityEngine; using System.Collections;

 [System.Serializable]
 public class Boundary 
 {
     public float xMin, xMax, zMin, zMax;
 }
 
 public class PlayerController : MonoBehaviour
 {
     public float speed;
     public float tilt;
     public Boundary boundary;
 
     public GameObject shot;
     public Transform ShotSpawn;
     public float fireRate;
 
     private float nextFire;
 
     void Update ()
     {
         if (Input.GetButton("fire1") && Time.time > nextFire) 
         {
             nextFire = Time.time + fireRate;
             Instantiate(shot, ShotSpawn.position, ShotSpawn.rotation);
         }
     }
 
     void FixedUpdate ()
     {
         float moveHorizontal = Input.GetAxis ("Horizontal");
         float moveVertical = Input.GetAxis ("Vertical");
 
         Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
         GetComponent<Rigidbody>().velocity = movement * speed;
 
         GetComponent<Rigidbody>().position = new Vector3
             (
                 Mathf.Clamp (GetComponent<Rigidbody>().position.x, boundary.xMin, boundary.xMax), 
                 0.0f, 
                 Mathf.Clamp (GetComponent<Rigidbody>().position.z, boundary.zMin, boundary.zMax)
             );
 
         GetComponent<Rigidbody>().rotation = Quaternion.Euler (0.0f, 0.0f, GetComponent<Rigidbody>().velocity.x * -tilt);
     }
 }