iCloud Unlock for iPads

I need assistance to unlock several iPads that are currently iCloud Activation Locked. These iPads were purchased from an official channel, but the seller forgot to unlock them.

Requirements:
- The iPads are iCloud locked.
- I do not have the original Apple ID and password.
- I can provide proof of purchase or documentation from the official channel.

Ideal Skills and Experience:
- Experience with iCloud unlock procedures.
- Familiarity with handling iCloud Activation Locks.
- Ability to verify proof of purchase and document authenticity.
- Previous success in unlocking Apple devices