To add custom fields such as gift messages or delivery/pick-up info to an order, follow these steps:
1. Click the "Add Field" button and search for the "Order Line Item Properties (User-defined)" field.
2. Add this field and navigate to the page where you can define any name and property, like "Engrave Name."
For example: "Engrave Name" (as in the sample of image below)
These steps are similar for note attributes too.