“put in extra hours”的意思是“加班工作、加班加点”。

【例句】
Workers are terrified of losing their jobs. This makes it easier to persuade them to put in extra hours or shoulder new tasks.
工人们害怕失业，这使得鼓励他们加班或干其它的活变得更加容易。

I have to put in extra hours this week to meet the deadline.
本周我不得不加班以赶最后期限。