I've found tutorials on how to do this in other versions of Presta but haven't seen anything that is confirmed to work 100% for Prestashop 1.7.5+. I'm creating a module that requires 1 or 2 customization fields per product and I want to simplify the process of ordering by eliminating the "Save Customization" button and having the customization saved when the add to cart button is clicked.   I've found this: http://nemops.com/save-prestashop-custom-fields-add-to-cart-2/#.XEyrgVxKiU