To apply for a patent is to apply to the China National Intellectual Property Administration Patent Office, pay the fees and patent application documents, including the request, specification, patent claim, abstract, etc. The audit process lasts 1-3 years, and may or may not be authorized in the end. After authorization, an annual fee should be paid to maintain the validity of the patent right.
To declare a project may be to submit a project declaration, test report and other materials to the Science and Technology Commission or some local relevant departments for approval.
What is important is that if the project is reported and the technical content is made public, you can't apply for a patent. On the other hand, if you apply for a patent first, even if you apply for the project the next day, the patent authorization will not be affected by publicity.