I2c on up4000

KrissNC

I'm trying to write something on an i2c LCD display.
up4000 seems to be 3.3v
the display is probably 5v since it works with an arduino.
mraa is not working atm (no clue why the github verision doesnt work)
do I need a level shifter (I bought one) ?

How can I have I2C work. (pins 3 and 5 on the hat connector are I2c One, right ?)
What kind of code can I use ?