Two approaches: one is the Paris Convention approach, that is, after applying to the State Intellectual Property Office, based on this application for priority, you can submit an application to a foreign intellectual property administrative department within one year. Of course, you can also apply directly to foreign intellectual property administrative departments, but because it often takes a long time to apply abroad, without priority, the application date will be delayed; at the same time, if you apply directly abroad, since there is no involvement from the State Intellectual Property Office, After a confidential review, the application will not be approved and authorized when submitted again in China.
The other is the PCT route, which is to submit an application document directly to the State Intellectual Property Office. The application type is PCT international application. When submitting the PCT application, you can choose the country where you plan to apply in the future, that is, designated country, so that the application can enter the domestic review stage of each country after passing the international stage. The PCT application method is relatively simple, but since the post-application review goes through the international stage and the domestic stage, the cycle is relatively long.
If you feel unfamiliar, it is safer to find a patent agency.