Restricted iPad can't buy stuff from the App Store

If your father has applied restrictions that disallow purchase of Apps, the restriction must be lifted to allow you to purchase and download using your credit. After you have downloaded/installed the App, the restriction can be re-applied.

As such, without help from your father, you’ll not be able to spend your credit.

If you continue to experience difficulties, you might be best advised to seek assistance directly from from Apple Support. You can contact the Support Team using the Get Support link at top-right of this page.

Alternatively, you can initiate and manage your support cases using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:

https://apps.apple.com/gb/app/apple-support/id1130498044