"Let's keep in touch."

Translation: 请保持联系。

[Astatine85210]

"保持联系吧" - 请 not needed and 吧 is a particle that can be used for suggestion

[Hedwigechouette]

"请保持联系" was rejected but I think it's ok on it's own without the 请

[Hedwigechouette]

btw my understanding is that Chinese don't use 请 nearly as much as we use "please" in English, plus please was never in the original English of this translation