Woocommerce

Hi,

Even if the products are available to buy, I have a
“please select some product options before adding this product to your cart”
in every product.

Here an example: https://umi1.co.uk/shop/shirt-with-pleated-back/

How can I fix that? Is it related to woocommerce?

Thanks

The page I need help with: [log in to see the link]