How to show supplier email in email field in non-catalog form?

Supplier email is entered at supplier setup level in "Contact Directory". And this is coming while creating the PO.

Requirement is to populate the same email in Non-Catalog request form in email field while creating the Purchase requisition.

Steps to generate this scenario:

1. Opened the non-catalog request page from iProcurement

2. Entered the Supplier name and site.

3. Email field is not populating automatically based on the email that is entered in supplier site under contact directory.