The Fighter archetype Arcane Archer gains the Arcane Shot feature at level 3. It also seems to be the most prominent feature of the archetype. But its description includes this:
when you fire a magic arrow from a shortbow or longbow (XGtE 28)
Which would mean that you need a way to fire a magic arrow. You do not necessarily have something like that at level 3. Is it a typo or do I understand it wrong?
Does taking the archetype force the DM to give you a magic item so that you can use it? Or should you simply not take it if you do not have a magical bow? There is no similar restriction on any other archetype.