Create and fund Adyen balance accounts for a platform using the Adyen Platforms API

Steps

1. Create an account holder via the Adyen Platforms API with the legal entity details of the sub-merchant; receive an accountHolderId in the response.
2. Create a balance account linked to the account holder; specify the default currency for the balance account.
3. Fund the balance account by processing a payment and routing the proceeds to the sub-merchant's balance account using the splits field on the payment request.
4. Use the balance account transfers endpoint to move funds between balance accounts or to initiate payouts to the sub-merchant's bank account.
5. Listen for ACCOUNT_HOLDER_VERIFICATION and BALANCE_ACCOUNT webhooks to track KYC status changes and funding events.
6. Query the balance account endpoint to retrieve current available, reserved, and total balances before initiating payouts.