Yap.Town

入れなくては

have to put in

→ 入れる
phrase Rare #45,889
have to put in Often followed by ならない or いけない to express obligation. It can also be used on its own when the rest of the phrase is understood.
JA: 車にガソリンを入れなくては。
EN: I have to put gas in the car.

ほとんど空なのでガソリンを入れなくてはなりません。

The tank is almost empty, so I need to get gas.