How to resolve carrier locked eSIM issue on iPhone 14 Pro Max?

The carrier that the phone is locked to are the only ones who can unlock the phone. Apple can't unlock it. If you can't contact them, then the phone is not usable.

Get your money back from whoever sold it to you.

The All Too Common SAD Reality of Buying a Used iPad/iPhone.

https://discussions.apple.com/docs/DOC-250001038

If you're trying to ask how to remove the carrier lock from your phone, only the carrier it is locked to can do that. You will have to contact them. There is not alternative.

If that's not what you mean, you need to clarify your question.

If the phone is carrier-locked, and there is no way to contact the carrier to whom it is locked, the phone is useless as a cellular phone.

You would have to contact the carrier to whom the phone is locked either to

• Sign up with that carrier, or
• Get the carrier lock removed so that you could use the phone with another carrier

Even if you can identify the carrier, there's no guarantee that they will unlock the phone. Especially if you are not their customer, or if there's an outstanding contract (e.g., the previous owner got the phone on a subsidized plan, and skipped out on that plan before paying all of the installments).