Updating payment info

I have 20 dollars in my account

See -> Check your Apple ID balance

Check your Apple ID balance – Apple Support (UK)

If you have add that 20 dollars, it would take 1 to 2 business days.

Sign in to your Apple ID account page and edit / update your Apple ID details.

https://appleid.apple.com

On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.

Or -> Change, add or remove Apple ID payment methods

Change, add or remove Apple ID payment methods – Apple Support (UK)

See also -> Payment methods you can use with your Apple ID

Payment methods you can use with your Apple ID – Apple Support (UK)

You can also use your Apple ID balance as payment method:

Add money to your Apple ID balance

Add money to your Apple ID balance – Apple Support (UK)