Custom Shopify coding for product notes upon add to cart

Job ID: 33057394

Budget: $30 – $250 AUD

We are selling a greeting card on Shopify that we handwrite the message to add to orders. We are looking to add a custom popup or box that appears upon greeting card add to cart, to add a message, and/or is a 'required field' on the product page that can't be added to cart unless it is filled out.

We are unable to simply use 'cart order notes' as people bypass this by using Shop Pay, Paypal etc.

FYI - We also want to be able to later install this product as an upsell, so the required message must be able to work with an upsell UX.
Related categories: Website Design eCommerce HTML Shopify Templates Shopify