Hello prachiz,
As you did not write, how you created the webhook, I would start from scratch:
Use the Adobe Workfront -> Watch Events module and create a webhook with
Record Type: Task
State: New State
Event filters: status Equals <status Key> (possibly CPL)
Exclude updates made by this connection - yes
Record Origin: Updated Records Only
This will trigger the Adobe Workfront Event Subscription API and do the work for you.
The status key can be found under Setup -> Project Preferences -> Statuses -> Tasks or under Groups -> <project group> -> Statuses -> Tasks.
So the parameters mean, that the Event listener / watcher checks for updated tasks and checks the values after the change (new State) for the status. If it is equal to the given key (e.g. CPL), the scenario goes on, if not, it does not run.
As you should check Exclude updates made by this connection to prevent letting the scenario going into a loop, make sure, that you use another user for your connection than the one you use when working in the Workfront UI and change the status of the task.
Regards
Lars