How to modify received Virtual Service request before routing

[Naveen4]

Hi all,

I want to modify the received request to the Virtual Service ( Running in VirtServer) before routing to the another API.
Could anyone please help me with this. Thanks a lot in advance

Eg : Received Request -> Modify Request Body -> Route to another API (Will use routing in the Virtual Service)

[nmrao]

Not enough details available. Please as much details as possible and add sample input and out  data (need not be exact)