IMPORTANT : to make it work, you will need the help of an additionnal ADC converter because the one on the ESP32 isn't accurate enough. Here we used an ADS1115 from Adafruit
You can find it here : https://www.adafruit.com/product/1085
And here is the library you'll need to add to your sketch : https://github.com/GreenPonik/Adafruit_ADS1X15
git clone https://github.com/GreenPonik/esp32-read-ec-example.git
cd esp32-read-ec-example
pio run -t upload
pio device monitor