how to add lines from supplier catalog to purchase order in buyer work center

In forms, to get price from a quote, user shall click on catalog, select a price from one of the source like negotiated documents or prior purchases.

How this can be achieved in BWC ?

I am trying in 12.2.4 by selecting the action add line from catalog. it takes to iprocurement and returns no results for the supplier,

I need to select a price from a approved quotation created in Oracle Sourcing.

Thanks

Siva