Unable to enter the DFF in the Additional information under "Create Invoice from Spreadsheet"

Descriptive Flexfield: Invoice Gateway Header

       To Create invoice using Spreadsheet with DFF values, Please use the below steps to define the Invoice Gateway Header or Lines DFF:

1. Go to Setup & Maintenance > Search and Select the task 'Manage Payables Descriptive Flexfields'
2. Search for the Name 'Invoice %