Activation Lock issue on used iPad Mini 3

Given what you have said, unless you were also given the receipt from when it was purchased from Apple or an Apple Authorized Retailer then there is nothing you can do but recycle it.

The long story:

Refer to https://support.apple.com/108934 There are only two ways to remove a lock:

#1 If you have the necessary information, you or the signed in owner can do this yourself by simply signing in with the owner account and password information and doing as instructed in the above article. If you use this method and this is a new device to you, follow unlocking by doing as outlined in https://support.apple.com/109511 or https://support.apple.com/HT201065 . If you do not have the required information then you can try method 2 —>

#2 Apple can completely reset a device if a person can provide sufficient evidence of valid ownership. Read the requirements and steps for an Activation Lock support request at: https://al-support.apple.com/#/additional-support and links at the bottom right for the type of service requested. Apple says they “may” require "proof of purchase documentation” and that you need “proof of ownership documentation”, but does not detail what currently constitutes proof other than it “must include the product serial number, IMEI or MEID.” User reports on this community and chat with Apple indicate that typically Apple will absolutely require, and ONLY accept, an original receipt issued by Apple or an Apple Authorized Reseller. Presumably this is the only kind Apple can authenticate against fraud since Apple is not involved in third party sales. Apple recommends that you "Keep your receipt after you buy an Apple device" --> https://support.apple.com/HT202711

Note that the device cannot have Lost Mode set on it or be a managed device. If your device has been taken over by you having entered a scammer’s Account then the scammer has likely set Lost Mode and the device is lost to you.

You do NOT have to be the “original” owner. In the case of removing the lock with the correct information, it can be anybody who knows the currently signed in account information. In the case of asking Apple to unlock it, as long as you have the original Apple receipt (which may well not have any personally identifying information on it) you are okay. Apple confirmed this in a conversation.

If Apple resets the device this will give you access to the device but won't restore access to the account used to lock it. There is nothing that can be done to expedite an Activation Lock request.

If you cannot get the device unlocked then read this section from the very bottom of https://www.apple.com/shop/trade-in :

"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 https://www.apple.com/ for free."

And read these for future purchases:

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

https://support.apple.com/104999

You won't be able to use that iPad. The activation lock is an anti-theft measure.

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