If you are working on a task, then you can rest assured that your contribution is completely anonymous. As a result, we cannot find you in our system unless we obtain your unique participant code. Otherwise, please contact us via the blue "Send Feedback" button at the top right of the task interface. This is always the best way to reach us in any situation, as it automatically gives us your participant number, a link to whatever task you were working on, and displays any questions you have missed. This information allows us to resolve your questions much more efficiently.
If this does not answer your question, please submit a request to our support team.