Set up a Yapily Variable Recurring Payments mandate and execute recurring payments against it

Steps

1. Verify the target institution supports VRP by calling GET /institutions/{institutionId} and checking the features array for INITIATE_DOMESTIC_VARIABLE_RECURRING_PAYMENT
2. POST /variable-recurring-payment-consents with applicationUserId, institutionId, and a controlParameters object specifying MaximumIndividualAmount, PeriodicLimits (amount and period), ValidFromDateTime, ValidToDateTime, and the mandate type (sweeping or commercial)
3. Redirect the user to the returned authorisationUrl; after successful authorisation the user is returned to your redirectUri with a consent query parameter
4. Store the consentToken and extract the consentId from the GET /variable-recurring-payment-consents/{consentId} response; verify the status is AUTHORIZED before initiating payments
5. Initiate individual payments by POST /variable-recurring-payments supplying the consentToken, amount, currency, and paymentIdempotencyId; each call initiates one payment within the mandate constraints
6. Monitor mandate health with GET /variable-recurring-payment-consents/{consentId}; check RemainingAmount and NextResetDate on periodic limits and alert before limits are exhausted