No additional fields defined for this line layout

What causes this issue?

For the selected line layout, the system configuration settings do
not contain any specifications concerning additional fields.

How to fix this error?

You may want to choose a line layout that contains the desired field
(if so, choose "Settings --> Line layout").
If you require additional fields for the set line layout, you must
ask your system administrator to change the display variant in the
Customizing system of Invoice Verification. For
the line layout, you can enter the fields to be used as additional
fields by choosing "Environment --> Field selection --> Additional
fields".

Error message extract from SAP system. Copyright SAP SE.