Hello,
You need to remove the default Add to cart button.
Please add this code to the Theme Settings > Custom CSS > Global:
body.single-product .cart,
body .woocommerce-variation-add-to-cart{
display:none;
}
Then follow these steps:
Create HTML block and insert the Popup element: https://xtemos.com/docs/woodmart/html-blocks-2/ and https://xtemos.com/docs/woodmart/shortcodes-2/
Then insert the contact form element/widget or shortcode into the content of the popup.
Add this HTM block into the Theme Settings > Single product > Add to cart options > Before “Add to cart” area.
Best Regards