Sorry, but no one here can check your IMEI to tell you who the phone is locked to. This is a user to user only forum.
If in Settings > General > About > Carrier Lock - nothing is listed, you could try this --> https://imei.org/check-imei/carrier
But be advised that even if you can find who the phone is locked to, they are under no obligation to remove the lock if you are not their customer or the phone, you likely purchased used has any unpaid fees on the account.
Apple cannot unlock any carrier locked phone. If you bought a used iPhone, you should read this --> The All Too Common SAD Reality of Buying … - Apple Community