Use Variable Amount in WSDK-Enabled Webstores

When the Variable Amount preference is enabled for an item record, the WSDK item script does not include an input box for the variable amount.

Add this sample input tag within the <form> tag of the Add Item to Cart HTML script in the Item Script Page of the record located in Setup > Site Builder > Preview Website > HTML and URLs for querying items :

<input name="amount" id="amount" size="10" maxlength="10"> 

This will create an input field to enter the variable amount for the item.