Connect K33 with Arduino Mega 2560 Rev 3

Using Arduino Sensors
1

Hello
Currently testing The K33 sensor with the Arduino to test CO2 readings via I2C. Which pins are used for I2C_SDA and I2C_SCL should it be pins 20 and 21 or the SDA and SCL from the top right of the Arduino?

2

if you occupying 20/21 you have no chance to put there something other and thinking this two are free, and technically pins 20/21 and the SDA/SCL from the top right of the Arduino are same pins.

3

Thank you!