The current code has a bug. The option GAIN_DIVIDE_6 is set to true however gain is set to 16x and those don't go together as already the comments says right at the GAIN_DIVIDE_6 code line.
So that option needs to be set to false.
Then the Lux values are correct. Before the fix they were a magnitude too low.

Hello,

The program is fixed: https://github.com/TinyCircuits/TinyCircuits-Wireling-Light-Sensor-AST1012/blob/master/examples/Light_Sensor_Wireling_example/Light_Sensor_Wireling_example.ino

Thanks for catching that and letting us know!

Best,
Réna