Hello Varun,
Thanks for your reply
But in my case, I am not using customer specific fields to capture Sold-to-Party for Project Definition.
I am using standard SAP delivered function i.e. Partner Determination Procedure to capture Sold-to-Party (in separate tab on project definition called "Partner")
So when I want to initially upload project definitions from legacy system, need to know BAPI to upload the same
BR / Mayur