How do I make a crouch script unity 3d

I just started learning to code in Unity and I wanted to create a crouch script by making the player's scale smaller, but it did not work; can you please help me understand what I've done wrong and fix my code and please make it as simple as possible?

 using System;
 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class Movement : MonoBehaviour
 {
     private bool JumpKeyWasPressed;
     private GameObject plr;
     private Vector3 scl;
     // Start is called before the first frame update
     void Start()
     {
         scl = gameObject.GetComponent("Player").transform.localScale;
         plr = GameObject.Find("Player");
     }
 
     // Update is called once per frame
     void Update()
     {
         // Jump
         if (Input.GetKeyDown(KeyCode.Space))
         {
             JumpKeyWasPressed = true;
         }
         // Right and Left movement
         float horizontalInput = Input.GetAxis("Horizontal");
         GetComponent<Rigidbody>().velocity = new Vector3(horizontalInput * 2.5f, GetComponent<Rigidbody>().velocity.y, 0);
         // Crouch
         if (Input.GetKeyDown(KeyCode.C))
         {
             gameObject.GetComponent("Player").transform.localScale += new Vector3(0.5f, 0.25f, 0.5f);
         }
         else
         {
             gameObject.GetComponent("Player").transform.localScale += new Vector3(0.5f, 0.5f, 0.5f);
         }
     }
 
     private void FixedUpdate()
     {
         // Jump
         if (JumpKeyWasPressed == true)
         {
             GetComponent<Rigidbody>().AddForce(Vector3.up * 5, ForceMode.VelocityChange);
             JumpKeyWasPressed = false;
         }
     }
 }