Why UFUNCTION dont work?

[anonymous_user_23644fc6]

Hello ! i try to make blueprint funtion with two input string nodes and one bool output.
this is my code:

h file
UFUNCTION(BlueprintCallable, Category = Client)
bool CheckInputs(std::string password, std::string login);
ccp file
bool UMyGameInstance::CheckInputs(std::string password, std::string login)
{

}

i try compile but have error (

[ryanjon2040]

Try this:

// header
UFUNCTION(BlueprintCallable, Category = Client)
bool CheckInputs(FString password, FString login); 

// source
bool UMyGameInstance::CheckInputs(FString password, FString login)
{
    // Do return logic
    return true;
}