How to apply for fee reduction after patent fees are filed?

From the day after the applicant submits the filing information in the system, the applicant can use the filing voucher number fed back by the filing system to submit a patent application and request for fee reduction: when submitting a patent application, just check "Request for fee reduction for qualification filing and fee reduction for completed work" in the patent application request; Where a fee reduction is requested after the filing date, it is necessary to submit a fee reduction request (applicable after the filing date) and fill in the patent fee reduction filing voucher number.