Chinas Z work visa

Hi i am Azizbek who is currently in china beijing i am going to get job visa here in beijing. But should i go to my country Uzbekistan Tashkent embassy to confirm my visa if yes what documents i must hold with me to enter to Chienese embassy in Uzbekistan. My chinese agency is doing a z visa for me what documents i need to recieve from my agency to get job visa. I got my health check certificate in Beijing what documents required to meto enter to the to the chinese embasy in uzbekistan pls write thank u