Infrared to Wi-Fi gateway from China

Hey! I tried to flash my device but I’m not able to do so. I’ve same board like one at @vanclec picture.

Is this config valid for flashing?
3.3V, GND + IO0, TXD, RXD. I tried also without 3.3V pin (with usb power).

No traffic on serial port? Could it be locked (the ESP8266 chip)?