How can I translate 不客气 here?
不客气 is a polite way of acknowledging someone's compliment or thanks. Although it literally translates to "don't be polite", once you consider some equivalent phrases, it's meaning becomes clear.

Equivalents in Chinese:


不用谢 - (no need to thank [me])
别客气


Equivalents in English:


You're too kind
Don't mention it
Not at all