The modal particle 吧 can be used at the end of an imperative sentence to express a suggestion. An exclamation mark is frequently used.
饭做好了,来吃饭吧!
Fàn zuò hǎo le ,lái chī fàn ba !
The meal is ready. Come and eat!
你有意见吗?现在就提出来吧!
Nǐ yǒu yì jiàn ma ?xiàn zài jiù tí chū lái ba !
You have some opinions? Why don’t you raise them now!
吧 can also be used to soften the tone of a command while making the sentence sound more casual than an imperative sentence with 请.
啊!老王,是你!好久不见!进来吧!
A !Lǎo wáng ,shì nǐ !Hǎo jiǔ bú jiàn !Jìn lái ba !
Ah, Lao Wang, it’s you! Long time no see! Come in!
[1] Yip, P. C., Rimmington, D., Xiaoming, Z., & Henson, R. (2009). Basic Chinese: a grammar and workbook. Taylor & Francis.