Question: Do Buddhists believe in fate or destiny?
Answer: The answer is at https://thedailyenlightenment.com/2014/12/why-no-one-truly-believes-in-predestination and the related links at the end of the article.
Briefly, while there are predispositions of what might happen due to past karma and present habits aligning now and in the future, past karma can be altered by present positive or negative efforts and habits, for better or worse, before it ripens.
There is only one kind of truly fixed destiny – when one practises the Dharma so well that one attains enlightenment of some level, or is bound to reach Pure Land to do so. All other matters are subject to change, when supportive conditions change.