how to set up Apple Savings with an ipad?

Currently, that is not an option. Apple Savings account must be set up using your iPhone.

Your iPhone must be updated to iOS 16.4.1 or higher. No exceptions. The links will not appear until you update.

Update iOS on iPhone - Apple Support

Once the update is complete, please follow the steps in this support article below,

Set up and use Savings in Apple Wallet - Apple Support

You’re welcome! Stay tuned and let’s hope that’s a future option.