I install the mod (forge version) and i can't open the menu. I search and I can't change the hotkeys and I don't have "litematica.json". I have 2 files .json but there is not "openConfigGui" inside them so currently I can't use the mods...

Do you mean in the 1.12.2 Forge version, or the unofficial 1.16.5 Forge port? In the 1.12.2 version you can open the mod config menus via the Forge mod list and the Config button that appears when you select a mod in the list.

And in the current mod versions the relevant Litematica hotkeys are called openGuiSettings and openGuiMainMenu.

I mean in the unofficial 1.16.5 forge port. I have also other mods so it can be the problem too

You said you don't even get a .minecraft/config/litematica.json config file? Is the mod even loaded? Do you see it in the mods list, and do you see the orange [Litematica] text on the F3 screen?

I will check again but I see the mod in the mods list and I see the orange [litematica] on the F3 screen

Okay I find it but i'm sure it was not here before and the mod was loaded...

I change the keybinds in the .json but it still not display the menu

Which keyboard layout do you have? Other layouts than QWERTY might have some of the keys in different locations, so the display name would unfortunately be wrong for some keys. Does neither M nor M + C work? What about the malilib config screen keybind A + C? Did you edit the config file while the game was closed or running? You need to at least be in the main menu when you edit it, and then when you log into the world the config should get loaded.

I have an AZERTY keybord and I change the keybind to "0" in the .json (so numpad 0). I change 'cause M didn't work before, same for malilib config and i edit while it was open so i closed the game, save the file and running again the game and it still didn't work

Numpad 0 would actually be called KP_0 in the config file, just 0 is the normal 0 on the main keyboard.

Okay it's working thanks a lot

I have a similar problem right now... Through mod menu can see litematica settings but M doesn't pull up in game. M + C doesn't work either... Currently running 1.18.2 on pojav

Update: turns out it doesn't like 3rd party keyboards. Changed back to standard built in keyboard and everything works as should

What do you mean by standard built keyboard ?