Sim is not Supported in unlocked iPhone

The only thing you can do is call Apple Care and give them the serial number. They should be able to tell you who it's Locked to.

Then contact that carrier and ask them if it's eligible to be unlocked.

No, the inclusion of a sim removal tool has NOTHING to do with carrier locks. Just got one of my two iPhone 11's yesterday. Paid in full, not carrier locked and it didn't come with a sim ejector tool. Most people just use a paperclip if there is no tool in the box.

Carrier locks are software. And ONLY the carrier can unlock a locked phone. No one else.

Having read what you did, it's clear when you restored the phone to factory, you removed whatever someone did to get this phone unlocked. It's pretty clear you own a carrier locked phone.

Your phone is locked. Period. End of discussion. You're like someone denying obvious medical symptoms in the hope that they aren't real.

A SIM ejector tool will come with any phone purchased from a store that sells country-specific phones that will lock to the first carrier they are used with in that country, and will not work outside of that country. Examples of such stores are Best Buy in the US and Carphone Warehouse in the UK, but there are others in other countries. The presence or absence of a tool is no indication of the lock status of the phone. Not to mention that the store you bought it from may have added a SIM tool; they are $9/100 from Amazon.

So most likely you bought a grey market phone that was originally purchased from one of the stores I mentioned and resold by your local dealer to you. The model number can tell you the country that the phone was intended to be sold in.

Those websites are frauds and scams. They are ways to get personal info about you which they then sell. You can use the Contact Support link at the top of this page and an Apple support rep can look up the SIM lock status.

Then you bought a locked phone, or a locked phone that had been hacked to unlock it. Once you restored iOS that removed the hack.

Did you buy the phone new or second hand?

That's an indication that the phone was NOT legitimately unlocked.

Reset - not update. Huge difference.

update wipes the entire phone and puts on iPhone software. Your phone was locked but some software was possibly hiding it then you wiped that software, and the phone recognized it was in fact, locked.

You can't tell whether a phone is unlocked based on the model number.

The website you got that from is giving you bad information.

EXACTLY where did you buy it?

The ONLY source for unlocked iPhones in the US is directly from Apple. If you bought it from any other retailer, you did not buy an unlocked phone.

Well.

It's not an unlocked device.

A physical sim has nothing to do with a phone being locked to a carrier. All phones can be locked to a carrier, yet they have removable sims. If a sim fails, how would one get a new one from their carrier if there wasn't a removable sim tray?

From where did you buy it?