Find another job.
There’s a small chance that you can negotiate a raise with your current job. Negotiation requires leverage. The ultimate leverage in a salary negotiation is competing job offers.
There are two things a competing job offer does in a negotiation. First, it gives you a better alternative to just taking the deal on offer. The second thing it does is give your demands for a particular number teeth.
I started a salary negotiation at a current job by forwarding a job posting to my boss that advertised a starting salary that was significantly higher than my current one. I did not get the advertised salary, but I did get a significant raise. So that’s an option if you don’t want to start putting out resumes and interviewing.
But I’d advise against it. You’re never going to get a market salary from a company that started out underpaying you. It just doesn’t happen. At least not without a) a competing job offer in hand, and b) a real reason for the company to want to try to keep you. For example if the disruption that would be caused by your departure is way more dangerous than just ponying up the cash.
You get a market salary from the market, not from an individual company. So get out there and put yourself on the market.