According to Article 30 of the current Patent Law, if an applicant claims priority, he shall make a written statement at the time of application and submit a copy of the first patent application document within three months; Failing to submit a written statement or a copy of the patent application documents within the time limit shall be deemed as not claiming priority.
The meaning of priority is: when applying for a patent, if you have applied for the same patent before (12 months), you can enjoy the filing date of the previous patent application when applying for this patent, provided that you have a patent application with the same content in front of you. The first patent application is not a priority.