get by

to be able to live or deal with a situation with difficulty, usually by having just enough of something you need, such as money:
How can he get by on so little money?
We can get by with four computers at the moment, but we'll need a couple more when the new staff arrive.
(Cambridge Advanced Learner's Dictionary & Thesaurus からの get by の定義 © Cambridge University Press)

アメリカ英語辞典
to manage or continue to exist in a state or situation where something is lacking:
When we were students we got by on very little money.
There is tremendous pressure on families trying to get by without health insurance.
(Cambridge Academic Content Dictionary からの get by の定義 © Cambridge University Press)

ビジネス英語
to be able to live or deal with a situation by having very little of something you need, such as money:
It was many years before she was in a financial position to do anything beyond getting by.
get by in/on/with sth She got by on what she made working at the deli.
(Cambridge ビジネス英語辞典 からの get by の定義 © Cambridge University Press)

- Cambridge Dictionary