VL53L0X sensor massive offset

I've bought a VL53L0X sensor board (SEN0245) and connected it as shown on the WIKI to an Arduino Uno

I've added the DFRobot_VL53L0X library to my Arduino libraries and I'm running the example.

Sure enough I get distance readings but they have a massive offset.

With the sensor face down on white paper the reading is 88.5mm, and is offset by this value no matter what distance I'm trying to read (e.g. 10mm reads 99.5mm, 100mm reads 188,5mm) etc

I read on the VL53L0X datasheet that we should perform a one time calibration, save some values and then write these values into the VL53L0X each time we start it up so that we get accurate readings.

How do we do that?

Thanks

K