Cards v3 Direct API Integration
The full card integration instructions are maintained in the Payins (v3) guide.
Use POST /v3/payment with a non-empty paymentData object containing valid card details or a saved card token. Missing or invalid card data can return HTTP 400 before a transaction is created. Other missing information or 3D Secure authentication can require a cashier redirect.
The guide includes card request examples, signature instructions, and retry behavior.