If you applied ScreenTime restrictions - and secured ScreenTime with a ScreenTime Passcode, you can only release this protection using the correct Passcode.
As a safeguard, to reset a forgotten ScreenTime Passcode, you have the option to use a recovery email address. The onus is upon you to ensure that you have access to the email account that you have used for Passcode recovery - as, if you lose access to the account, you also lose the ability to reset the associated Passcode. In such circumstances you can still recover full use of the device - but will have no alternative other than to fully reset the iPad, a process that will erase all locally stored data.
You are in the unfortunate predicament of having enabled multiple technical layers of security - individually designed to protect your device and data from potential compromise. Having forgotten an essential Passcode, and lost access to the recovery email account, you cannot remove the protection without fully resetting the iPad.
Assuming that you are the bona-fide owner and retain access to the iPad itself, you will need to manually back-up any critical data and files that are stored locally on the device prior to resetting the iPad. Any data synchronised with iCloud will remain accessible and available after resetting the iPad.