Cepat! Jika tidak, kita akan terlambat.

English Translation

Hurry up! If you don’t, we’ll be late.

“Kita” should be replaced with “kami”. “We” in this context suggests that “we” are traveling in the same group. “Kita” is used when “we” includes people not in the conversation. I heard from an Indonesian teacher that some native speakers misuse “kita” in this situation as a “broken” language. But the sentence use a formal expression “jika” (if). It doesn’t match the sentence.