How to test the swimming health certificate?

When you go to the swimming pool, people in the museum will do it for you. Actually, it's just a formality, not very strict. But every place is different, just go to the swimming pool and ask. I remember that this kind of health certificate seems to be only 5 yuan, and it is all made by the swimming pool itself. Generally, large swimming places only require tourists to have health certificates, and swimming pools should be able to do so, and they are very cheap.