This article is pretty old, but I think all the information is still very relevant. It's the best-written instructions I've seen on the subject, so I refer back to it whenever I need a refresher.

For jam games, I guess using the input system is probably overkill, but I find it to be very helpful and I'm trying to completely abandon the old input manager anyway.

https://gamedevbeginner.com/input-in-unity-made-easy-complete-guide-to-the-new-system/#inputactionassets