The health certificate shall be issued by the health and epidemic prevention department. Nan 'an District Epidemic Prevention Station is on the other side of Furen Road, namely Luojiaba Road, in the same building as Chongqing Nan 'an District Maternal and Child Health Hospital. Bus No.833 goes there.
However, many industries or units require municipal health certificates. You'd better ask clearly and make sure it is the health certificate issued by Nan 'an District Epidemic Prevention Station. If not, you have to go to Xiaojiawan epidemic prevention station.