This is a new method that is convenient for inspection. The traditional way is for an individual to take a small plastic box, put a small stool in it, and then give it to a doctor for examination.
It seems to be to test malaria and other diseases. I'm not sure about that. Anyway, as long as there is a physical examination, there must be a convenient examination for this.
It doesn't matter whether you have your period or not, it won't affect you.