Enhancing the Order form

To enhance the Order form, update the doGet function as follows:

function doGet(){
  var template = HtmlService.createTemplateFromFile("Order");
  template.pricelist = getPrice();

  var html = template.evaluate();
  return HtmlService.createHtmlOutput(html);
}

The price list is assigned to the template as a 2-dimensional array and is returned by the function shown here:

function getPrice(){
  var data = SheetStock.getDataRange().getValues();
  
  // remove header row.
  data.shift();

  return data;
}

In the Order.html file, update the select tag markup as shown in this code snippet:

<td>
  <select id="item" name="item">
    <? for(var i in pricelist){ ?>
      <option value="<?= pricelist[i][0] ?>" > <?= pricelist[i][0] ?></option>
    <? } ?>
  </select>
</td>

The drop-down items will reflect whatever is included or updated in the Stock Sheet. The default item will be the top-most or the first item in the list...