The supplementary statement of international express shows that please upload a photo of your real ID card. What does it mean?

Supplementary declaration of international express shows that please upload a real ID photo, that is to say, you need to upload a real ID photo, because "Regulations of People's Republic of China (PRC) Customs on Inbound and Outbound Express" stipulates that when declaring personal belongings for inbound and outbound express, the operator should submit the Declaration Form of Personal Articles for Inbound and Outbound Express of People's Republic of China (PRC) Customs to the customs, the waybill of each inbound and outbound express, the copy of the identity certificate of the recipient or sender of the inbound and outbound express and other documents required by the customs.