I would like to use ESP-12F using I2C, however the official documentation is not clear about SCL / SDA pins on the chip. I would like to know which pins should be used for SDA / SCL on the chip. BTW the firmware is Tasmota.
All I did was Google the ESP-12F and the first result was THIS. On page 14 it tells you the I2C pins needed.
Go up to page 8/9 for the pinout description.
The Tasmota firmware uses the esp8266 Arduino core. The Wire library in esp8266 Arduino uses software I2C. It can use any pair of suitable io pins. Default pins for most esp8266 variants are SDA 4 and SCL 5.