it shouldn't be possible.

If you are engaged in catering, you need to get a health certificate and syphilis. This situation can be spread through contact. If you have such a disease and are engaged in catering, it is also an irresponsible behavior for others, which will endanger their health and may cause others to be infected. If you have a health certificate, you need to check infectious diseases, including hepatitis B and syphilis, so you should not be able to get a health certificate in this situation.