If you’ve accessed Stripe Issuing’s test-mode through the dashboard, your account lets you try out basic functionality like creating cards, testing transactions and testing physical card shipment (but not creating real cards).
This is a temporary state, and once you go live, you'll lose access to any cardholders and cards you've created from this test mode.
Speak to sales to configure your account, get approved for a supported business use case and get access to both live mode and ongoing test mode.
Don't build a full API integration until you've spoken to sales.
You can also test Issuing with connected accounts and Treasury. This lets you onboard test users with connect accounts, issue cards, and provision FDIC insurance eligible financial accounts.
Other configurations are only available to test once you're approved by sales. Those configurations include Charge Card functionality, beta options for funding card spend, approval to create company cardholders (instead of individual), and access to additional transactional data, like gallons of fuel pumped for Commercial Fleet Cards.