To unlock your iPad, follow the steps described in the Apple article:
(< iOS 15.2) If you’ve forgotten your iPad passcode
If you’ve forgotten your iPad passcode – Apple Support (UK)
(iPadOS 15.2 and newer) If you see an iPhone or iPad unavailable message or Security Lockout screen
If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support
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See -> If you can't connect or sign in to iCloud
If you can't connect or sign in to iCloud - Apple Support
Have you forgotten your Apple ID?, Check your Apple ID via your email box, see this Apple article: If you forgot your Apple ID
If you forgot your Apple ID email address or phone number - Apple Support
OR see -> Having trouble signing in?
https://iforgot.apple.com/password/verify/appleid
Have you forgotten your password?, See -> Change your Apple ID password -> Change your Apple ID password - Apple Support
Then see this Apple article: What to do after you change your Apple ID or password
What to do after you change your Apple ID or password - Apple Support
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BTW:
You are sign in here . . . with your Apple ID & Password.
Your Apple ID is the personal account you use with all Apple products and services. It includes the email address and password you use to sign in, as well as the contact, payment, and security details that you use with Apple.
You can’t merge multiple Apple ID accounts.
What happens when you use the same Apple ID & Password that you use to sign in here?
See -> Sign in with your Apple ID -> Sign in with your Apple ID - Apple Support
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For more support and assistance see -> Indonesia
or call direct to -> 0800-1-027753
