Hi Sunil,

In order to extend customer as vendor, you need to follow below steps:

1. Open Customer (BP)

2. Click on Change Mode

3. Add new role FLVN00 for FI info, FLVN01 for Purch info

4. Enter the details in Company Code and Purchasing Org tab

5. Save the BP

For more details, watch BP video provided to you in course videos.

Regards, Team Gaurav