请 (qǐng) can be used at the beginning of an imperative sentence to soften the tone of a command and make the speaker sound more polite or courteous. Note that, in English, ‘please’ can appear at the end of the imperative sentence, whereas 请 cannot.
English: Come in, please. Have a seat, please. Have some tea, please.
Qǐng jìn 。qǐng zuò 。qǐng hē chá 。
 Yip, P. C., Rimmington, D., Xiaoming, Z., & Henson, R. (2009). Basic Chinese: a grammar and workbook. Taylor & Francis.