Management requires direct reports: you make decisions which directly impact the careers of other people.
Leadership can be more subtle than that. You can influence people without needing to directly manage them.
John Carmack at Facebook/Meta is a great example. He was an IC - they had to invent a new level of the IC ladder for him! Definitely a leader, not a manager (at that company).
(Amusingly, I got to attend some "leadership" classes at Stanford a while ago. My main takeaway was that the way to create leaders is to put a bunch of people in a room and tell them that they're "leaders" until they start to believe it.)