When a delivery location is a required field on a document, it is usually because it has been set up as required on the document type.
 
1. Navigate to Document types, search and drill into the relevant document eg.  Purchase Order (Quantity). In the General tab, the Delivery address required is marked which would require the delivery address on Purchase orders. Edit.
 
 
2. Uncheck the Delivery address required box. Save the changes.
 
Now, when creating a Purchase order, the Delivery address is no longer a required field.