FAGLL03 PO Number Does not Show

Hi,

We are generating a report from FAGLL03.  However, the Purchasing Document field is blank. As seen below:

In the GL Account, we have set the sort key to 0014 Purchase Order (see image below). 

Yet the PO still did not show up in the PO field (see the first image).  Kindly help and assist.

Thanks,

Matt