Shopify Custom Field Required

I added code to for a custom field and to make it required but it only works when they Add to Cart. It doesn't work when they click Buy it Now. I need what they put in the field to show up in all orders.

Also when they fill out the custom field they cannot click add to cart or buy it now until they click somewhere else on the page and then it allows them to buy.

Budget for this is $20.