I fixed it by removing the module method above and using these codes:
Header:
#pragma once
#include "Engine/DeveloperSettings.h"
#include "CurrencySetting.generated.h"
UCLASS(config = CurrencySystem, DefaultConfig)
class CURRENCYSYSTEMRUNTIME_API UCurrencySetting : public UDeveloperSettings
{
GENERATED_BODY()
public:
UCurrencySetting();
UPROPERTY(Config, EditAnywhere, meta = (ClampMin = "0", UIMin = "0"))
int StartingAmount;
};
CPP:
#include "CurrencySetting.h"
UCurrencySetting::UCurrencySetting() : StartingAmount{}
{
CategoryName = "Plugins";
SectionName = "Currency System";
}
Result: