Can I transfer my Apple ID balance to apple cash

You can’t transfer your Apple Account balance to another payment method. From the article below.

About unused Apple ID balance

You can't redeem or return Apple Gift Cards, App Store & iTunes Gift Cards, or unused Apple ID balance for cash, except as required by law. If your jurisdiction allows for refund of redeemed gift balances, you can contact Apple Support to request a refund. - When you contact Apple, please include the following information:

Your Apple ID.   -

The refund amount.

Your current shipping address.

Apple ID balance - View  *

Hi,

I'd suggest contacting the iTunes Store Support Team as they would be able to provide what options you have for this.

Contact - Official Apple Support

Contact Apple for support and service - Apple Support

Cheers,

- Sean