This tutorial provides step-by-step instructions for how to implement Steam Input for games developed in Unreal Engine 5.1. I will mostly be covering how to do things in BluePrints using the EeelDev SteamCore plugin, but some C++ will be covered as well. The SteamCore plugin is just a wrapper for the Steam Input API, so going back and forth between C++ and BluePrints should be relatively simple.
https://dev.epicgames.com/community/learning/tutorials/qM7o/unreal-engine-steamworks-input-api