Dear Samuel
I am Zhang Su the international sales manager of STONE and you question has been well noted.
You need to weld the above marked R601 resistance in order to shift the UART interface of your display from RS232 to TLL in order to communicate with your Arduino.
In addtion, I have sent email to you but it has been rejected by your email proxy. Could you please offer your whatsapp number so that would be helpful for having more efficent communication in future.
Best regards
Zhang Su