Well if you have an italian keyboard layout & a multimedia keyboard you can't expect it to work out of the box. You have to change your keyboard layout in LibreELEC settings to get your keys interpreted as italian layout and you have to probably have to change the language in Retroarch to italian too.
Also I'm not entirely sure what you're going to remap and what purpose this serves. In the end it makes not much sense to use any emulator without a proper gamepad
Anyway there is a complete documentation available for such topics Input and Controls - Libretro Docs
Well, it seems your use of retroarch is somewhat limited if you're not considering all the retroarch hotkeys you can use during gameplay (volume up/down, for example, or save/restore state, or change save slot). Gamepads are for playing, keyboard is for managing retroarch
As already said, in kodi and chrome the keyboard is working fine, so it's obvious I've already applied the right configuration in kodi for my keyboard layout
I wrote to you because, as already said, only in retroarch the keyboard layout is totally wrong. And, if YOU read the libretro docs link you sent to me, there's nothing about configuring/fixing keyboard layout (I've already read it before writing to you the first time, and this is the third for the same problem)
So, please, don't think every question people ask to you are "waste of time"... I thought maybe you hardcoded something in retroarch binaries that messes up the layout... In retroarch installed on the official LE9 build my keyboard layout was right... it must be something in your retroarch implementation
In retroarch configuration there's nothing about keyboard layout... you can only configure mappings... but, if you want to map "-" key for volume down and when you press it in the mapping it maps "f3", you see... the layout is wrong...
Thank you