What is the origin of “give it the beans!”?

There’s a phrase, possibly specific to British English, to “Give it [some/the] beans!” when referring to a task that somebody should put more effort into. It’s similar to “Give it some welly!”.

What I don’t know is.. what are the beans? Why am I giving them? And to whom?

I had a look around online and other than quite a few people acknowledging that this is something they say, I didn’t find much authoritative evidence for why we say it.

surely it's a stand in for give it some gas. if this pre-dates the automobile then I would say cowboy speak is likely the origin.