iPad locked after multiple login attempts, how to unlock it?

If iPhone isn’t responding, and you can’t turn it off then on, try forcing it to restart.

Refs.:

Force restart iPhone - Apple Support

Force restart iPhone - Apple Support

This article tells you the various ways you can try to discover your forgotten Apple ID --> If you forgot your Apple ID - Apple Support Typically an Apple ID is an email address you have used. If you are currently using a mobile device that is logged into your account, go to Settings and tap your name at the top. Look in Keychain, and in a browser's security settings if you use it to automatically sign into Apple when using a browser.

This article outlines what to do If you forgot your Apple ID password --> If you forgot your Apple ID password - Apple Support

or go directly to this link --> http://iforgot.apple.com/

If you find you can’t sign in, reset your password, or receive verification codes, you can request account recovery (read this support article: How to use account recovery when you can’t reset your Apple ID password - Apple Support ) to regain access to your account. Account recovery might take a few days or longer, depending on the specific account information you can provide to verify your identity. More detail in —> Activation Lockout Issues - Apple Community

If you still need help this page provides country-specific Apple Support contact information ➞ Contact Apple for support and service - Apple Support

If you see a waiting period you can try again after the timer ends. If you wish to proceed with resetting, or if it is disabled/security lockout/unavailable, refer to this support article for various methods that you can use to resolve this. --> https://support.apple.com/HT212951 Which one you can use depends upon your equipment configuration. If you can use the iOS15.2+ method you may not need a computer.

How to reset your device if you are running iOS 15.2 or later:

Advance step: If you're using an eSIM, contact your carrier before trying these steps and ask for a QR code to set up your eSIM again.

1. From your device's Lock Screen, try to enter your passcode five times until the "[Device] Unavailable" screen appears and your device asks you to try again later.

2. When you're able to, continue to enter your passcode until the "Security Lockout" screen appears and you get the Erase [Device] option in the bottom corner of the screen.
 3. Tap Erase [Device], then tap Erase [Device] again to confirm.

4. Enter your Apple ID password to sign out of your Apple ID on your device.

5. Tap Erase [Device] to permanently delete all of your data and settings.

6. When your device restarts, follow the onscreen instructions to set up your device again, restore your data and settings from a backup, and set a new passcode.

You can only reach the "Security Lockout" screen if you have an active cellular or Wi-Fi connection and previously enabled Find My ( https://support.apple.com/find-my ) on your device. After you try to enter your password ten times, your device will either erase itself or show Security Lockout and the option to Erase [Device] without a timer, depending on how you previously set up your device. 

If you can't follow the above steps (e.g., you are using an older iOS version), you can use a computer to reset your device, as described in this article --> https://support.apple.com/kb/HT204306 .

Read the support article for full information. You can also watch the 5 min. 16 sec. Apple video "How to restore your iPhone if you forgot your passcode" at https://www.youtube.com/watch/7s8-zLG9ySQ

Whichever method you use will result in erasing the iPhone. You have no alternative. You can, however, restore it from a backup as described in this support article --> https://support.apple.com/HT204184 Some items will restore automatically once you make sure you are signed into iCloud (if you were using iCloud to sync these services).

Here are resources if you are prompted for your username and password and have forgotten them:

https://support.apple.com/HT201354 Note that typically this is an email address you use.

https://support.apple.com/HT201487

If you do not have a computer, use the link https://locate.apple.com/country to find an Apple service location, or ask a friend if you can use theirs. This could be either a Mac, or a PC with iTunes. If your computer doesn't recognize your iPhone, iPad, or iPod, read this support article --> https://support.apple.com/HT204095