With the new iPad, is it mandatory to use Touch ID

TouchID is not mandatory. You can also lock your iPad with

a PIN code - numeric or alphanumeric.

This link may provide you a good start:

https://support.apple.com/guide/ipad/set-a-passcode-ipad997daf9f/ipados

Significant elements of iPad functionality are reliant upon a Passcode being set. The use of TouchID (and FaceID on some models) is, however, entirely optional. If you don’t wish to use TouchID, you simply do not need to configure this feature - or you can either fully or selectively disable its use.

Specific details of setting and managing your Passcode and TouchID can be found in these support pages:

Set a passcode on iPad - Apple Support

Set up Touch ID on iPhone - Apple Support