If we identify ourselves with our physical bodies (our EGO) than we dont have free will because your entire existance as a limited being is decided by external factors. When you realise that bountry between your body and external world doesnt exist (your lungs are just as important for your existance as trees and sun, therefore they are just as much of yourself as lungs) you may also come to a realisation that entire reality has free will behind it, which means you also have free will because you are everything.