There are several ways you can increase a higher credit limit. You have to go through your lender directly, which usually means contacting your credit card company. Most of the time, you can make a request online through your account portal.
You can also call the card issuer and ask for a credit limit increase. Sometimes a credit card company will also send offers for you to raise your credit limit if you have been making all your payments on time. If they send you an offer to increase the limit, it will usually come with instructions on how to take the offer and request the limit increase.