Create a new payment from one of your accounts to a beneficiary.

Payment Options: You must specify the payment recipient using one of these options:

• beneficiaryId: ID of an existing approved beneficiary
• creditorAccountId: ID of another account you own (for internal transfers)
• beneficiary: Full beneficiary details for a one-time payment (beneficiary will be created automatically)

Idempotency: Use the externalId field to ensure idempotency. If you submit the same externalId twice, the second request will return the original payment details rather than creating a duplicate.

Currency Matching: The payment currency is always the source account's currency (the account given by accountId). The beneficiary must use the same currency. For cross-currency payments, use the Currency Conversions API.