Parameter Missing or Invalid: Items - Product

[abeaufort]

Hello, 

I'm getting a "Parameter Missing or Invalid: Items" error when I add a product button to our Shopify homepage.
We recently changed the product quantity from pack size to just a quantity selector . What's the code needed to fix this, and where do I place it? 

Site: www.nullwines.com
Theme: Debut version 17.12.1

[marcoswata]

Can you double check if your button is inside a form, with a valid quantity and variant ID inputs? 

(I don't see it in your homepage, if you have a preview link, we can help)

When adding an item to the cart, you may have encountered the error Parameter Missing or Invalid: Required parameter missing or invalid. This error occurs when you don't submit a variant ID or quantity amount with your Add to Cart form.
Source

[abeaufort]

Hi Marcoswata,

Here's a preview of the product button:  https://nullwines.com/pages/image-test

Where do I check if my button is inside a form, with a valid quantity and variant ID inputs? 

[marcoswata · Accepted solution]

Right click on the button and inspect element.
You will see the buttons are inside a form, but there is no variant ID or quantity.

You can understand better about product forms here:

https://shopify.dev/themes/architecture/templates/product

I suggest you take a look at your featured-product.liquid (or similar) and just copy the form from there, and modify it.