Big Commerce Store Cart Data In Local Storage Then Push to gtm at later stage

BigCommerceStoreCartDataInLocalStorage.js

//Added script to order-confrirmtion.html page 

    //store data after payment has been actioned
    $("body").on("click","#checkout-payment-continue" ,function () {
        var CratItems = {{{json cart.items}}};
        var Cart = {{{json cart}}};
       
        StoreCartItems(CratItems);
        
        //console.log(localStorage.getItem('transactionItems'));
        
        StoreGeneralCartInfo(Cart);

        //console.log(localStorage.getItem('transactionTotal'));
        //console.log(localStorage.getItem('transactionTax'));
        //console.log(localStorage.getItem('transactionShipping'));
    });
    
  function StoreCartItems(items){

        var TransactionItems = [];
        for (var i = 0; i < items.length; i++) {

            var item = items[i];
            
            var SKU = item["sku"];
            var Name = item["name"];
            var Quantity = item["quantity"];
            var Price = item["price"].value;
            var Category = "";
            
            var ItemToStore =
                {
                    'sku':SKU,
                    'name': Name,
                    'category': Category,
                    'price': Price ,
                    'quantity': Quantity
                };

            TransactionItems.push(ItemToStore);

        }

        localStorage.setItem('transactionItems', JSON.stringify(TransactionItems));
    }

PushCartDataInLocalStorageToGTM.js

//Added to chcekout.html page 

    PushGTMCartData();
    function PushGTMCartData(){
        var orderid  = {{{json checkout.order.id}}};
        window.dataLayer = window.dataLayer || [];
        dataLayer.push({
            'transactionId': orderid,
            'transactionAffiliation': '',
            'transactionTotal': parseFloat(localStorage.getItem('transactionTotal')),
            'transactionTax': parseFloat(localStorage.getItem('transactionTax')),
            'transactionShipping': parseFloat(localStorage.getItem('transactionShipping')),
            'transactionProducts': JSON.parse(localStorage.getItem('transactionItems'))
        });
    }