hùzhào liú zài chuāngkǒu qījiān, yào bǎoliú zhǐzhì huízhí, yě kěyǐ pāizhào bèifèn

护照留在窗口期间，要保留纸质回执，也可以拍照备份。

While your passport is at the counter, keep the paper receipt, and you can also take a photo as a backup.