If you need to apply for a Chinese patent, submit an application to the State Intellectual Property Office. If you need to apply for a foreign patent, submit an application to the Patent and Trademark Office of the country/region where you need to apply.
The general application process is: Patent search (optional) - Prepare application materials - Submit an application - Patent Office review (including formal review, disclosure, substantive review and other steps) - Authorization/rejection
You can refer to this article "How to apply for a patented product?" What is the process of patent application at home and abroad?》