Zapier does not have a working integration to create an estimate in quickbooks with shipping. In order to solve this you can create a custom zap with this code.

Zapier: Create Quickbooks Estimate with Shipping

var des = bundle.inputData.description;
var qty = bundle.inputData.qty;
var rate = bundle.inputData.rate;
var serv = bundle.inputData.service;
var servID = bundle.inputData.serviceID;
var shippingAmount = bundle.inputData.shipping;
var desFin = des.split(',');
var qtyFin = qty.split(',');
var rateFin = rate.split(',');
var servFin = serv.split(',');
var servIDFin = servID.split(',');
//enter all data as comma sperated values

var i, len, text;
for (i = 0, len = desFin.length, text = []; i < len; i++) {
  text.push({'Description': desFin[i] , 'DetailType':'SalesItemLineDetail', 'SalesItemLineDetail':{'TaxCodeRef': {'value': 'NON' }, 'Qty': qtyFin[i], 'UnitPrice': rateFin[i], 'ItemRef': {'name': servFin[i],'value': servIDFin[i]}}, 'LineNum':  i , 'Amount': qtyFin[i]*rateFin[i], 'Id': i });

}
text.push({'Amount' : shippingAmount ,'DetailType' :'SalesItemLineDetail','SalesItemLineDetail': {'ItemRef': {'value': 'SHIPPING_ITEM_ID' }}});

var options = {
  url: `https://quickbooks.api.intuit.com/v3/company/YOURIDHERE/estimate?minorversion=51`,
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${bundle.authData.access_token}`,
    'Accept': 'application/json'
    
  },
  params: {


  },
  body: {
  "DocNumber": bundle.inputData.docNumber,  
  "TotalAmt": bundle.inputData.amount, 
  "BillEmail": {
    "Address": bundle.inputData.email
  }, 
  "CustomerMemo": {
    "value": bundle.inputData.memo
  },
  "CustomField": [
   {
    "DefinitionId": "1",
    "Name": "YOURCUSTOMFIELD1",
    "Type": "StringType",
    "StringValue": bundle.inputData.customField1
   },
   {
    "DefinitionId": "2",
    "Name": "YOURCUSTOMFIELD2",
    "Type": "StringType",
    "StringValue": bundle.inputData.customField2
   }
  ],
  "Line": text,
  "CustomerRef": {
    "name": bundle.inputData.customer, 
    "value": bundle.inputData.customerValue
  },
  "ShipMethodRef": {
   "value": bundle.inputData.shipVia,
   "name": bundle.inputData.shipVia
  },
  
} 
      
    
  
}


return z.request(options)
  .then((response) => {
    response.throwForStatus();
    const results = response.json;

    // You can do any parsing you need for results here before returning them

    return results;
  });