EC800G CN Micro Python PIN BLINK

Hi, I have EC800G CN model. I want to use with QuecPython. The problem is that, I want to blink for example GPIO3 but don’t work. I ceck other pins, still don’t work. But in my code debug, everything is true. How can I do? Please help me. This is important to me for UART-485. because I use MAX485. I will control MAX485 chip. Problem is that, my device can send message other device over max485 but don’t recieve.

I’m sorry for the late reply.
May I ask which pin you are using? I think the problem might be that the wrong pin is being used.
Here is the pinout diagram of the EC800G. Please mark the pins you are using so that I can confirm.