Why creating constructor Failed?

MyGameModeBase.h

UCLASS()
class PUZZLE_API AMyGameModeBase : public AGameModeBase
{
    GENERATED_BODY()

public:

    MyGameModeBase();   //explicit type is missing('int' assumed)
};

MyGameModeBase.cpp

    #include "MyGameModeBase.h"
    
    AMyGameModeBase::AMyGameModeBase()  //no instance of overloaded function matches the specified type
    {

}

Solved:

public:
 
     AMyGameModeBase();