How to use custom fields when working with Scope Item 4E9?

Hello!

My name is Eduardo and I work in the Product Support for Professional Services.

I would like to share this question in the community as this is a question that I receive through incidents.

When using Project Billing, if you are using a custom field in the billing item from the billing tab of plan customer projects, after you create the billing document, if you display the billing document in Display Billing Document app the custom fields are empty.

How can I use custom fields when using Scope Item 4E9?