How to add context to a task report

 When I run a query a!queryProcessAnalytics with parameter contextProcessModels it gives me error

errorMessage=contextProcessModels was not null, but the report XXXX without context [id=XXXXX] does not use a context. (APNX-1-4275-007)]

I have tried with a new task report created from scratch I can add context of process model.

However, I could not find a way to add context to existing task report. Is there a way to add context to existing task report.

thanks

Nikhil