Adding Custom Fields to Order Form Receipts/Notifications

One of our order forms has a custom (html) drop drown that maps to the contacts custom field.

Is it possible to add this data to the notification/order receipt we receive when a client orders? If so, how?

I see the option to customize the receipts that clients receive when shopping from the storefront. However, I don’t see an option to customize their order form receipt or the notification that we receive.