Sales document type & not assigned to a billing document type

What causes this issue?

Sales document type &V1& is not assigned to any billing document type.
Document type &V1& is assigned to rebate arrangement type &V2&
("subsequent settlement") for partial or final settlement purposes.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

An order-related billing document type must be assigned to the sales
document type.
Please maintain the field <LS>Order-related billing document type</>
for sales document &V1& or assign a different, suitable sales document
type to arrangement type &V2&.
INCLUDE 'NA_CUST_MAINTAIN' OBJECT DOKU ID TX
IF &DEVICE&='SCREEN'
<DS:SIMG.SIMG_CFMENUOLSDVOV8>Define sales document types</>
<DS:SIMG.SIMG_CFMENUOLMEOMHD>Define rebate arrangement types for
subsequent settlement</>
ENDIF

Error message extract from SAP system. Copyright SAP SE.