postal code for Gubei, changning

FedEx refuses to send a package without a valid postal code. I have given them "200000" for changnig district but they tell me that it is not valid. my chinese address is 上海巿长宁区黄金城道777弄2号8A室. can you please help me confirm the postal code i am using is correct? thank you.

this is what I sent to them because they want the address in english:

Changning District,Huangjincheng
dao 777,Building 2 Room 8A,
Shanghai,
200000,
China