If you sign off on something, that means you approve it.

" sign off on" 的意思是赞成某事。

" To sign off on (something), " two words, means to approve, to say yes.

“To sign off on (something), ”两个词，意思是批准，同意。

I've heard of companies that require the boss sign off on something, like a leave, for longer periods of time.

我听说有些公司要求老板在某些事情上签字， 比如休假，时间更长。