Register a custom console command from c++ in unreal engine.

CustomGameInstance.cpp

// Example for registration of a custom console command.
// Use a custom game instance and override method Init from UGameInstance.
void UCustomGameInstance::Init()
{
    Super::Init();

    // Register a custom command to load a map.
    if (!IConsoleManager::Get().IsNameRegistered(TEXT("LoadMap")))
    {
        // Remove existing command.
        IConsoleObject* LoadMapConsoleObject = IConsoleManager::Get().FindConsoleObject(TEXT("LoadMap"));
        if (LoadMapConsoleObject != nullptr)
        {
            IConsoleManager::Get().UnregisterConsoleObject(LoadMapConsoleObject);
        }

        IConsoleManager::Get().RegisterConsoleCommand(
            TEXT("LoadMap"),
            TEXT("Empty help / description"),
            FConsoleCommandDelegate::CreateUObject(this, &UCustomGameInstance::LoadMap));
        }
    }
}

void UCustomGameInstance::LoadMap()
{
    // Do something e.g. load a map.
}