That’s why Congress should act on something called “trade promotion authority.”

因此，国会应该在“贸易促进授权法案”上有所作为。

" To act (act) on" something is to take something you believe and do something about it – to actually change your behavior based on something you think or believe in.

“采取行动（行动）” 是指接受你相信的事情并为此做一些事情——根据你的想法或相信的事情实际改变你的行为。