https://medium.com/@ashwinjitsingh/the-trolly-problem-utilitarianism-vs-deontology-bd624a8e321e

If one were to take a utilitarian standpoint, the means are justified by the end, which from a utilitarianist perspective, is the maximization of benefit. Hence, for a utilitarianist, whatever option guarantees the outcome of the maximum benefit is what is moral. Therefore, in the trolly case, a follower of classical utilitarianism would say that it is morally permissible to sacrifice 1 to save 5.

The deontological perspective in contrast, advocates for the means justifying the end. This, for a deontologist, the morality of the action should be based on whether the action itself is right or wrong under a series of rules, rather than being based on the consequence. In this light, a follower of deontologism would argue that it is morally impermissible to sacrifice one to save five because making the choice of having to kill someone is inherently wrong.

Again, this is the entire point of the trolley problem. No one actually give a shit about the hypothetical trolley. The whole point is to explore how different ethical systems can lead to different outcomes. There is no “right answer” to the trolley problem.