Man's fate is decided by heaven? Or are people in charge?

According to the eight-character theory of fate, the date of birth is predestined (the date of birth of a caesarean section baby is not decided by himself). But there is a kind of life that changes at will. No matter what a person's fate is, as long as he is committed to doing good, he will be rewarded. It has been an unbreakable truth for thousands of years that good is rewarded with good and evil with evil. From this perspective, people's fate still depends on themselves.