来なきゃ

if (someone) doesn't come, have to come, must come

→ 来る
来 come; arrive + なきゃ Must; have to
verb · informal Rare #44,681
if (someone) doesn't come Informal contraction of 来なければ.
JA: 君が来なきゃ、始められない。
EN: If you don’t come, we can’t start.
have to come, must come Often used as a contraction in 来なきゃいけない; the rest of the phrase may be left unsaid.
JA: 明日は早く来なきゃいけない。
EN: I have to come early tomorrow.
Conjugation of 来る
Necessitative
来るべき来なきゃ

石田→私来なきゃよかったな

Ishida → Me: I shouldn't have come.

— 映画 聲の形 (2016)

お前らが来なきゃ俺は死んでた

If you guys hadn't come, I'd be dead.

— エリート・スクワッド (2007)

毎年ここに来なきゃ。

I have to come here every year.