The modal particle 吧 can be used at the end of an imperative sentence to express a suggestion. An exclamation mark is frequently used.
Fàn zuò hǎo le ，lái chī fàn ba ！
The meal is ready. Come and eat!
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.
A ！Lǎo wáng ，shì nǐ ！Hǎo jiǔ bú jiàn ！Jìn lái ba ！
Ah, Lao Wang, it’s you! Long time no see! Come in!
 Yip, P. C., Rimmington, D., Xiaoming, Z., & Henson, R. (2009). Basic Chinese: a grammar and workbook. Taylor & Francis.