My iPhone is locked after factory reset

Hey there,

we are users like you not Apple!

If your SIM is locked by a PUK/PIN code see this article ☞ Use a SIM PIN for your iPhone or iPad - Apple Support, but if you see this error [SIM not supported] see this article ☞ How to unlock your iPhone for use with a different carrier - Apple Support

What is unavailing? The link?

if so this is a copy from that link ;

Your iPhone might be locked to your carrier. Unlocking your iPhone means that you can use it with different carriers. To contact your carrier and unlock your iPhone, use these steps. 

If you don’t want to switch carriers and your device is locked because you forgot the passcode, then you don’t need to use the steps in this article. Learn how to reset your passcode.

Apple can't unlock your iPhone for use with a different carrier. Only your carrier can unlock your iPhone.

Contact your carrier

1. Only your carrier can unlock your iPhone. Contact your carrier and request an unlock. Your account might need to meet requirements for unlocking. After you submit the request, it might take a few days to complete. Contact your carrier to check the status of your unlock request.
2. After your carrier confirms that they unlocked your iPhone, follow the steps below. 

If you have a SIM card from a carrier other than your current carrier

Use these steps to finish unlocking your iPhone:

1. Remove your SIM card.
2. Insert the new SIM card. Your device will activate.

If you don't have another SIM card to use

Use these steps to finish unlocking your iPhone:

1. Back up your iPhone.
2. After you make a backup, erase your iPhone.
3. Restore your iPhone from the backup you just made.

Get help

You might see this message on your computer or on your iPhone: "The SIM card inserted in this iPhone does not appear to be supported. Only compatible SIM cards from a supported carrier may be used to activate iPhone. Please insert the SIM card that came with your iPhone or visit a supported carrier store."

If you see this message on your device with iOS 14, use these steps:

1. Go to Settings > General, and tap About.
2. Under Carrier Lock, you should see a message that says "No SIM restrictions." If you don't see that message, contact your carrier.

If your device is on iOS 13 or earlier, use these steps:

1. Contact your carrier to make sure that they applied the unlock in their system.
2. Restore your iPhone to factory settings.
3. Restore your iPhone from a backup.

Yes I know so it told you to click on the second link to learn what to do!

click on this link ☞ https://support.apple.com/en-us/HT201328

Click on the second link to learn what to do!