Ardupilot not found external compass "LS3MDL" of XL RTK

I bought XL RTK and I found problem when I use pixhawk board with ardupilot.
Pixhawk not found external compass “LS3MDL” , How can I fix it?

Do you have any other way to test the LIS3MDL over I2C communication port using an Arduino dev board ?
Doing so you can easily figure out what is wrong.
Still if it is not working go there :
Nice day