Can you downgrade to Win10 from laptop with Win11 pre-installed?

I’ve been unhappy with my current laptop and had started looking for a replacement. I think I’ve found one but it comes with Win11 preinstalled. If I don’t like Win11, is it difficult to roll back to Win 10? Can it be easily done without having to purchase a copy of Win10?

Oops, forgot, I have a recovery flash drive from my Win10 laptop, will that work on a Win11 laptop?

Sorry for all the questions, but I’ve got to make a decision while it’s on sale for $300 off!