The subject wants to ask "how to refund the campus card of Nanjing University?" The refund steps are as follows:

1. Open the Nanjing Citizen Card APP, find and click the "Entity Card" option in the main interface.

2. Select the card face to be returned in the entity card list, and click to enter the card face details page.

3. On the details page, click the "I want to return the card" button after finding it and start to return the card.