First of all, you can communicate your feelings with the teacher and express your idea that you don't want to wear women's dance clothes. You can give your reasons, for example, you feel uncomfortable or you feel more comfortable in men's dance clothes. You can try to get to know the teacher and find a solution that can meet your needs and test requirements.
If the teacher insists that you wear women's dance clothes, you can consider wearing your own dance clothes, or report your situation to the Education Bureau and ask their opinions.
Most importantly, don't let this question affect your study and performance. Focus on your dance skills and performance, so that your dance becomes the highlight of the inspection.