First, open the cponline.gov.cn of China Patent Electronic Application Network, register first, and the account name is your ID number;
Second, after registration, log in to external services and download digital certificates;
Third, downloading CPC clients from the tools of China Patent Electronic Application Network can submit application documents and receive official documents.
If it is an offline application, it is also called a paper application. You can mail the application documents directly to the acceptance office of China National Intellectual Property Administration Patent Office at No.6, West Tucheng Road, Jimenqiao, Haidian District, Beijing, with the postal code of 100088.
Both of the above methods need to produce application documents. The application documents include the request, the claim, the specification, the appended drawings of the specification (the invention can be without drawings) and the abstract of the specification. The template can be downloaded from China National Intellectual Property Administration, I hope it will help you.