To add the order's custom field or gift message, please follow these steps:
1. Click on the Add Field button, and search for Order Line Item Properties (User-defined) field.
2. Then, try adding the "Order Line Item Properties (User-defined)" field.
3. It will navigate to this page and you can define any name. It also can define the property name.
For example: "Engrave Name" (as in the sample).
These steps are similar for note attributes too.