These are the two reasons why the Extensible Flexfield (EFF) is not visible in the order capture additional information section. An EFF is a user-defined flexfield that you can use to capture additional information on sales orders, such as trade compliance, call center details, or source order status1. To make an EFF visible in the order capture additional information section, you need to perform the following steps2:
Associate the EFF context with the page: You need to specify which page in the Order Management work area will display the EFF, such as the order header or the order line. You can use the Pages tab in the Manage Order Extensible Flexfields task to associate the EFF context with the page.
Publish the custom extensible flexfields: You need to deploy the EFF to the database and make it available for use. You can use the Deploy Flexfield task to publish the custom extensible flexfields.
Reference:
Overview of Setting Up Extensible Flexfields in Order Management
Set Up Extensible Flexfields in Order Management
[Manage Order Extensible Flexfields]
[Deploy Flexfield]