Without claiming the Task, user can be able to complete the task through REST API, how to restrict it?

Hi Camunda Team,

I have a task in camunda tasklist, and without claiming the same task by the user, I’m able to complete the same task through REST API. How to make sure that only claimed tasks only can be completed through REST API (can we add any validation for it? I know from UI we cannot complete the task without claiming but from REST API how to do that).

Below is the request that I have tried to hit from postman. I’m getting success response and the task is completed and verified in Database as well.

Can anybody help me on this please.