Apply discount code from cart page in shopify

cart.liquid

<div class="discountcodefield"> 
  <label for="discount">Discount Code:</label> 
  <input autocomplete="off" type="hidden" name="discount" class="discount_code" />
  <input autocomplete="off" type="text" name="discount_code" class="discount_code_field" /> 
  <input type="button" name="apply_discount_code" class="btn discount_code_btn" value="Apply"/>
</div> 

<div class="cart__savings discount_apply_code">
</div>

<script type="text/javascript">
$(document).ready(function() { 
  $('.discount_code_btn').click(function(){ 
    var discountStored = $('input[name="discount_code"]').val();   
    $('input[name="discount"]').val(discountStored); 
    $('.discount_apply_code').html('<div>Discount code <strong>'+discountStored+'</strong> applied on checkout page. <a href="javascript:void(0);" class="clear-discount">X</a></div>');
    localStorage.setItem('storedDiscount', discountStored); 
    $('input[name="discount_code"]').val('');
  });
  
  $(document).on("click", 'a.clear-discount', function(event) { 
    var discountStored = '';
    $('input[name="discount"]').val(discountStored); 
    $('.discount_apply_code').html('');
    var deletenum = 'storedDiscount';
  localStorage.removeItem(deletenum);
  });
  
  if (localStorage.getItem('storedDiscount')){ 
    var discountStored = localStorage.getItem('storedDiscount'); 
    if(discountStored != '' && discountStored != 'undefined'){
      $('input[name="discount"]').val(localStorage.getItem('storedDiscount')); 
      $('.discount_apply_code').html('<div>Discount <strong>'+discountStored+'</strong> applied on checkout page. <a href="javascript:void(0);" class="clear-discount">X</a></div>');
    }
  }    
});
</script>

checkout.liquid

Put the below code into checkout page

<script>
      (function () {
        var jquery = null;

        if (window.jQuery) {
          jquery = window.jQuery;
        } else if (window.Checkout && window.Checkout.$) {
          jquery = window.Checkout.$;
        }
        
        jquery(document).on("click", 'button.applied-reduction-code__clear-button', function(event) {
          var deletenum = 'storedDiscount';
          localStorage.removeItem(deletenum);
          var url = window.location.href;  console.log(url);
          var return_url = removeURLParameter(url, 'discount');
          window.location.href = return_url;
        });
        
        jquery(document).on("click", 'button.field__input-btn', function(event) {
          var value = jquery('#checkout_reduction_code').val();
          updateQueryStringParam('discount', value);
        });
        
      })();
      
      function removeURLParameter(url, parameter) {
        //prefer to use l.search if you have a location/link object
        var urlparts= url.split('?');   
        if (urlparts.length>=2) {

          var prefix= encodeURIComponent(parameter)+'=';
          var pars= urlparts[1].split(/[&;]/g);

          //reverse iteration as may be destructive
          for (var i= pars.length; i-- > 0;) {    
            //idiom for string.startsWith
            if (pars[i].lastIndexOf(prefix, 0) !== -1) {  
              pars.splice(i, 1);
            }
          }

          url= urlparts[0]+'?'+pars.join('&');
          return url;
        } else {
          return url;
        }
      }   
      
      // Explicitly save/update a url parameter using HTML5's replaceState().
      function updateQueryStringParam(key, value) {
        baseUrl = [location.protocol, '//', location.host, location.pathname].join('');
        urlQueryString = document.location.search;
        var newParam = key + '=' + value,
            params = '?' + newParam;

        // If the "search" string exists, then build params from it
        if (urlQueryString) {
          keyRegex = new RegExp('([\?&])' + key + '[^&]*');
          // If param exists already, update it
          if (urlQueryString.match(keyRegex) !== null) {
            params = urlQueryString.replace(keyRegex, "$1" + newParam);
          } else { // Otherwise, add it to end of query string
            params = urlQueryString + '&' + newParam;
          }
        }
        window.history.replaceState({}, "", baseUrl + params);
      }
    </script>

Quick question - this solution will only work for Shopify Plus customers, as other than that "checkout.liquid" file is not visible, right ?