Where does “なくちゃ” come from?

なくちゃ (Japanese) comes from Japanese なくては（ならない）.

なくちゃ (Japanese): must, have to; if one doesn't.

Definitions

Step	Language	Word	Meaning
1	Japanese	なくては（ならない）	—

なくちゃ — Etymology, Origin & Word History | Etymology Explorer