Plenty of people with the title "manager" aren't actually leading anyone. Plenty of people with no title at all are who the whole team quietly orients around. The title and the leadership are two different things.
Watch any team long enough and the pattern is obvious. When something goes wrong, people don't turn to the biggest title in the room. They turn to whoever's been calm, competent, and honest the longest.
You don't become a leader when someone gives you a title. You become one when people start looking to you for direction.
That's good news if you don't have a title yet. You're not waiting on anything external. The behaviors below are available to you right now, in your current role.
Don't confuse any of this with self-promotion. Leading without a title means being the person others can depend on, often quietly. Not making sure people notice how capable you are. The credit arrives later, as a reputation, not a single moment.
At some point, if you're carrying real leadership weight without the title to match, that gap is worth naming, to yourself and eventually to whoever can change it. That conversation goes better once you've built the track record than if you try to have it first.