I think you have to list them as Physical product if it is a made to order product even for the digital
Could be wrong, there is another section
We’re super excited to announce some changes that we’ve made to the listing and delivery process for made-to-order digital listings.
When you create a digital listing, you can now list it in two different ways—an instant download or made-to-order.
“Instant download” means you’ll upload the file when you create the listing and your customers will receive it immediately when they make a purchase. You can upload audio, image, or text files to your listing. No changes here!
With this new made to order listing process, if you offer custom digital products, you can choose to list a digital item as “made-to-order.” If you 1) specify the listing is “made-to-order” in the “About this listing” section and 2) also specify that the listing is “Digital” in the “Type” section, the item will be referred to as a "made-to-order download.” Note: If you have existing listings that fall under these parameters and would like them to be recognized as made-to-order, you’ll need to delete the file(s) associated with the listing.
https://community.etsy.com/t5/Announcements/We-ve-improved-our-made-to-order-digital-listing-experie...
