Apple and the issuing bank, Goldman Sachs, do not state a specific dollar amount. But it’s a requirement that you show the means to payback the funds you borrow. If you don’t show that you have the means, your application will be denied.
It’s a standard practice in the credit card industry to use household income. This includes people living in your household that you have reasonable access to their income, such as a spouse. Investment income and other sources can be included.
Please review the information in the Apple Support article I shared below.
How your Apple Card application is evaluated – Apple Support