I did successfully get QR codes "working" in Espruino, but used an ESP32 for the Wifi. Being lazy, I just got a QR code generator and put it on a server then downloaded the image to the ESP32 and displayed it as an image. There are lots of websites to generate QR codes, so that might work for you also.
I couldn't get it to work on an OLED screen (128x64), but had some success with an ST7789 AND ILI9341. This could have been due to the type of QR code I was using at the time.