What’s my credit line

To view your Apple Card credit limit, see the following from: Set up iPhone to get SMS messages on Mac - Apple Support

View your Apple Card credit limit and credit details

On your iPhone:

1. Open the Wallet app and tap Apple Card.
2. Tap the More button , then tap Card Details .
3. Scroll to Credit Details to see your account Credit Limit, Available Credit, and APR.

On your iPad:

1. Open the Settings app.
2. Scroll down and tap Wallet & Apple Pay.
3. Tap Apple Card, then tap the Info tab.
4. Under Credit Balance you can see your Card Balance, account Credit Limit, Available Credit, and APR.

FoxFifth wrote:

To view your Apple Card credit limit, see the following from: Set up iPhone to get SMS messages on Mac - Apple Support

Most likely you mean -> View your available Apple Card credit details or request a credit limit increase

View your available Apple Card credit details or request a credit limit increase - Apple Support

Thanks -- pasted the wrong link (not the first time unfortunately)!