"Invalid approval route code" when entering an OD purchase order

Hello Oracle Community,

I have a user attempting to enter a new OD purchase order and they are receiving the following error:

Invalid Approval Route Code

A form level error has occurred.
Cause. . . . . The Approval Route Code is not defined in the Approval Levels
               file (F43008) for the order type.
Resolution . . If the approval process is desired, then the Approval Route Code
               must be defined in the Approval Levels file (F43008) for the
               order type.  The processing option determines the Approval Route
               Code that is used as a default.  If you are currently using the
               the P.O. Header video, place the cursor on the Approval Route