Negotiating levels after a year in PayPal

Is it possible to get one’s levels updated for actual experience. I got a raw deal while joining and the primary reason I didn’t negotiate then was because I was on a break and working as a volunteer. So I had $0 as base to negotiate from and had taken a pay-cut for a startup before that (in hand was same) but could not wait till equity allocation while leaving. Secondly I was going through a personal family issue that had me grieving and didn’t have the mental bandwidth to do back and forth. Long story short I have close to 16 years of experience and 10 years in product but am at L25 and am unhappy about it. Ive had enough time to see how folks are placed against levels in terms of experience and skill level and am clearly at a much lower level than what I should be at. My options are internally negotiate if feasible or leave with other offer(s). I would love to know if the first is an option. If yes do I initiate with HR or my manager. My manager has already spoken of looking at next level during the first year appraisal. #productmanager #pm #product