Can I pay the balance of my Apple Card from my Apple ID balance.

I don’t believe you can. Apple Cash won’t allow gift card balances to be transferred. The only thing you can do is use those gift cart balances to purchase items or services from Apple.

What you can buy with your Apple ID balance - Apple Support

Contact iTunes Support to see if they can/will transfer the money. See the Apple Support articles below for contact information.   

iTunes Support – world wide 

Apple Support schedule phone call      

If necessary, try Twitter

https://twitter.com/AppleSupport.          People have posted it may take an hour or more to get a response.

No. AppleID balances can only be used to pay for Apple products or services. Your Apple Card balance is payment you owe to a Goldman Sachs Bank.