Hi Atul,
You have to setup the control copy in the following path:
Transaction SPRO > Customer Relationship Management > Transactions > Basic Settings > Copying Control for Business Transactions > Define Copying Control for Business Transaction Types
Make also sure that:
- You have authorizations for followup transaction
- Followup transaction is allowed for webui channel
- Also I would recommend to activate this setting (more info on note 661305): SPRO > Customer Relationship Management > Transactions > Settings for Activities > Activate Copying Control for Activities
Check if it helps you a little more.
Kind regards,
Garcia