After installing the CedCommerce Purchase Order extension, the admin has to enable the Purchase Order extension.

To enable Purchase Order extension

1. Go to the Admin panel.
2. On the left navigation bar, click the STORES menu, and then click Configuration.
   The Configuration page appears.
3. In the left navigation panel, click the B2B EXTENSIONS menu, and then click B2B Extensions Configuration.
   The Configuration page appears as shown in the following figure:
   
4. In the right panel, under B2B Purchase Order, in Enable B2B Purchse Order List, select Yes.
5. Click the Save Config button.