JDBC / How to get return parameters from Oracle Function

Hello,

I am able to call Oracle function but I am not able to get return parameters. Call is bellow :
(just renamed parameters to save sapce, Yx are input parameters, Xx are output parameters and all are defined in JDBC test step)

DECLARE 
RetVal NUMBER;
BEGIN 
RetVal:= MATVADM.METER_READING_PKG.calculate_f(:Y1,:Y2,:Y3,:Y4,:Y5,:Y6,:X1,:X2,:X3,:X4,:X5,:X6,:X7,:X8,:X9,:X10);
END;

Could someone help me out, please?
log says function was executed but my properties remains empty.
Can somebody help me, how to get return parameters from function?