Using 5V I2C pin to power 5V sensor

I’m kinda new to electronics and the Seeeduino stalker. I wanna use the Stalker to power a 5V sensor. The -ve is connected to ground and the sensor input is connected to an ADC port. For the +ve, I need to connect it to a 5V pin. It seems that one of the I2C pins can provide 5V. Which I2C pin should I use? Can I turn the sensor on and off from the sketch by writing a high and low voltage to this pin?

Many thanks!

The pin on the side is 5V, but it is stable, and can not be controlled by any sketch.