Reply to Having difficulty with me headphone buttons to work

Watsup everyone I'm Paul, I'm new to DJing, I picked up a Vestax vci-100 SE with tracktor pro 2 and an Alesis io2 interface. I'm having difficulty getting my headphone buttons to work, I press the buttons but nothing comes ons, I've been searching on google to see if anyone has the same problem but could not find anythings, so I'm wondering if anyone came across the same problem or is it that I'm missing something, I would really appreciate the help. Thanks