After completing your task, it is taken into evaluation. You can see your task under review from the task history in the profile section.

In order to access your task history, you must click on the area indicated with a red frame on the screenshot below while in your profile. In this way, you can access your task history and see your approved and rejected tasks, as well as the reasons for rejection.

When you click on the rejected task, you will see the message that explains the reason for rejection.