You need to show us the message from the gradebot so we can help you faster. Usually when this happens, it’s because something was not done as specified.
The problem is that your service client is exiting too quickly, as suggested in the first point mentioned by gradebot below. We think the service should take at least 10 seconds to complete. Please adjust your logic accordingly.
I tested my code, I send the command so that the robot turns at the specified velocity for 10 seconds and the robot executes the task in 10 seconds, but it is still graded as wrong. Or are the 10 seconds meant for something else?