I installed led halo headlights. They flicker no matter if it's DRL or if I turn the headlights on. The lights came with anti flicker canbus but they don't work. If I buy a flashcal will that fix the flickering.

 

A flash cal is not going to fix your problem. You need the proper resistors/ load resistors/ capacitors/ anti-flicker harnesses and you need them to work. Ensure you've got a quality product before you start throwing cash at it, otherwise you'll just be throwing the cash away.