How do I unlock an iPhone 13 Pro locked by the previous owner?

If you see a "Locked To Owner" message, one referring to iCloud locked, or activation locked:

Read this article about removing Activation Lock --> How to remove Activation Lock - Apple Support To remove the lock you will need either:

-The account information that set the lock (if the previous owner is deceased, read —> Request access to a deceased family member’s Apple Account - Apple Support )

OR

-The original sales receipt from Apple itself or an Apple approved vendor. Other ways you may think might be “proof” of ownership or purchase, such as having the box, or a receipt from a third party vendor such as Ebay, will likely not be acceptable by Apple. Apple may have no way of verifying the authenticity of other methods. If you have an acceptable receipt, ask Apple to unlock the device —> https://al-support.apple.com/#/additional-support

If anybody tells you that you have to be the “original” owner, they are incorrect. As long as you have the original Apple receipt (which may well not have any personally identifying information on it) you are okay.

If it is asking for an account that is not yours, take it back to the person from whom you received it. Get them to do the things in this support article or ask for a refund --> What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support There is no way to discover the owner of a device unless they left a message to display on the device when it is turned on, or the person who gave you the device knows them. Note that the device cannot have Lost Mode set on it. If your device has been taken over as a result of you having entered a scammer’s Account then the scammer may have set Lost Mode too and the device is lost to you.

Return or recycle the device if you cannot unlock it; it is useless to you. From the very bottom of Apple Trade In - Apple :

"Does Apple offer recycling?

Yes. Apple Trade In lets you recycle any Apple device (including devices from Apple-owned brands) at any Apple Store and on Apple for free. That includes your batteries and old electronic products as well as free, on-demand packaging recycling for our commercial, education, and institutional customers. When we receive your device, it will be thoroughly inspected to determine if components can be recycled or reused. Whether recycled or reused, all activities relating to the processing of your device will be managed in an environmentally responsible way."

When considering future purchases read these:

The All Too Common SAD Reality of Buying … - Apple Community

If you want to buy a preowned iPhone - Apple Support

Hello ~ That is the activation lock. If the person/persons that you bought the iPhone from cannot or will not remove it …the iPhone is basically useless to you. If they cannot/will not remove it…return it and get your money back. We cannot help remove it nor can Apple. Take a look here…

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Also…

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

~Katana-San~

Thank you for reaching out. 🤗

According to Apple:

Remove Activation Lock on the device

Follow the onscreen steps to enter the Apple Account and password you used to set up your device or your device passcode. If you don't remember your Apple Account, try to sign in with an email address or phone number that you regularly use for Apple services.

Learn how to find your Apple Account or reset your Apple Account password.

If your device is owned by a business or educational institution, please contact your IT department or manager. 

Remove Activation Lock on the web if a device is offline

For iPhone, you might be able to remove Activation Lock on the web even if your device isn't offline.

1. Go to www.iCloud.com/find.
2. Sign in to your Apple Account.
3. Select the device that you want to remove from iCloud.
4. Click Remove This Device.

Start a support request

If you need help removing Activation Lock and have proof of purchase documentation, you can start an Activation Lock support request.

Thanks again for reaching out. 👍🏼

Take care! 👋🏼😉

Smiliñ 😎 Brian | Community Volunteer

I think you will find that it is not so easy to remove ("I'm gonna remove") the Activation Lock (anti-theft lock).

The All Too Common SAD Reality of Buying a Used iPad/iPhone – Apple Community