If you are not centrally managing your company IT assets (such as iPad) and allow your employees to configure/activate their Apple devices with their own AppleID - you might be well advised to review your termination/exit procedures to ensure that IT assets are properly returned by the employee with the Activation Lock disabled.
Here are the Apple support pages that outline the Activation Lock - and the only mechanisms by which it can be turned off:
Activation Lock for iPhone, iPad, and iPod touch - Apple Support
Turn off Activation Lock – Apple Support
As you will discover, unless you are the owner of the AppleID that was last used to activate the device, or unless you can secure the cooperation of the previous owner, you’ll not be able to defeat or bypass the Activation Lock. Without documentary evidence that you are the original owner (such as sales receipt showing the serial number), Apple won’t assist - and nobody here will be able to help you. If you do have the original purchase invoice for the device, then Apple will usually assist.
Otherwise, if you are the owner of the AppleID that previously activated the device - and you have forgotten your AppleID or associated password, these can be recovered here:
https://iforgot.apple.com
To recover your credentials, you’ll need access to one of the following:
- Your primary email address mailbox that corresponds with your AppleID
- Any of the secondary/recovery email addresses that should be configured for your AppleID account
- Any of the trusted telephone numbers (fixed line or Cellular/Mobile) that are associated with your AppleID
Unless you AppleID account has not been fully/correctly configured, or has been seriously neglected, recovery of the AppleID and password should not be difficult.
More information about recovery of your AppleID:
https://support.apple.com/en-us/HT201354
More information about recovery of your AppleID password:
https://support.apple.com/en-us/HT201487
When you recover access to your credentials, you would be well advised to log-in to your AppleID account from a web browser - and verify/update any email addresses and trusted telephone numbers:
https://appleid.apple.com
For future reference, here is the procedure that properly prepares an iPad for reuse - wiping all data and removing the Activation Lock - after which the device is ready to be set-up again “as new”:
What to do before you sell, give away or trade in your iPhone, iPad or iPod touch – Apple Support
I hope this information and guidance proves to be helpful in with resolution of the problem.