Card Terminal
Take a payment over the phone — key in the customer's card and charge it.
New charge
Stripe isn't connected yet. Add STRIPE_PUBLISHABLE_KEY and STRIPE_SECRET_KEY as backend secrets (use test keys — pk_test_… / sk_test_… — first), then reload.
Test mode: use card 4242 4242 4242 4242, any future expiry, any CVC/ZIP.