[Free][Windows only] UE4Duino 2 - Arduino (COM port) communication

Hi all UE4Duino users and really thanks for your great work @ .
I am testing some arduino + blueprint codes without success so far and I kindly ask for help.


Those images are my Arduino code and my blueprint code, I do not know what I am doing wrong my main goal is sending from UE4 string ON to Arduino and Arduino must read it and activate 2 digital pins.
EDIT: LogTemp:Error: Failed to open port COM3. Error: 00000006 this is what I have achieved, COM port is not opening neither working. Have tried so far, 3 differents usb ports + hub (2 ad 3.0).
Any help? Really thanks and best regards!