In a patent application, how long does it take after paying the substantive examination fee to receive the substantive examination notice?

The "Patent Examination Guidelines" stipulate that a request for substantive examination should be submitted within three years from the date of application, and the substantive examination fee should be paid within this period. The substantive examination procedure for invention patent applications is mainly initiated based on the applicant's request. In other words, while paying the substantive examination fee, a request for substantive examination must also be submitted.