The normal question is meaning, rather than purpose. I interpret purpose in life as, what our job is, what we should be doing or focusing on. Outside of religion where there are generally clear answers, offering universal answers has become increasingly less popular in philosophy - and those that do generally provide more like general guidance, even where it's wrapped up in a term.
I would say there is guidance that can be drawn from how religions construct meaning, even for non-believers, through a proper understanding of how they form social cohesion around holding up specific stories and ways of being, discussed here: What are some philosophical works that explore constructing meaning in life from an agnostic or atheist view?
"The unexamined life is not worth living" -Socrates
Plato saw our purpose as to attain our higher self, something clearer more fundamental and universal, like pure mathematics is drawn from specific objects.
Aristotle described our telos, purpose or aim, as eudaimonia, which literally translates as good-spirited, but given how he draws it out from his botanical studies as it being how a seed seeks to manifest it's nature, we can better translate as 'human flourishing'. In the Stoic tradition they use the same term eudaimonia, and interpret as 'living in accordance with nature'. For each of us it will be different, so really eudaimonia means seeking our own picture of our nature or spirit, and understanding from that what it means for it to flourish. A seed doesn't have loads of choices on the way to being it's kind of plant or tree, whereas humans do..
Epicurus had our aim as ataraxia, achieving sustainable pleasure which leads to a state of tranquility and freedom from fear. That seems like parameters to find our purpose within, guiding habits that enable free action, rather than what our job is.
Kant grounded his thinking in universal principles, so he could use that to make universal claims, saying the purpose of human life is to understand and fulfil universal principles, like the categorical imperative. Hume's observation that we cannot get an 'Ought' from an 'Is' basically puts a bullet between the eyes of finding a universal purpose to life if you accept his reasoning, and his thought 'awoke Kant from his dogmatic slumbers'.
"Of all things the measure is Man, of the things that are, that they
are, and of the things that are not, that they are not" -Protagoras
I would say subsequent traditions are either humanistic, in this tradition of Protagoras, including Absurdism which aims at constructing purpose even while recognising it is in a deep way futile. Or nihilistic, saying there is no purpose beyond the temporary or illusory.
Philosophy is therapy according to Wittgenstein, where we could say purposelessness is a spook generated by bad use of language.
Durkheim shifted to looking at humans in action, in terms of anomie and suicide vs binding together through enactment of shared values, which constitute living together with a community's own internally-defined purposes.
I would describe the modern trends in philosophy as more like 'toolbox' approaches, that follow the Postmodern's recognition there is no universal framing or metanarrative we can expect everyone to share. Instead, pockets of cultures defined by their specific discourses, which we should ask more limited questions about to understand the dynamics of groups and cultures, which might include a specific understanding of purpose illustrated by choices actions or works.
