Changes to Create Merchant

removed the enum value 2026-01-01 from the header request parameter X-API-Version

removed the optional property error from the response with the 400 status

removed the optional property request_id from the response with the 400 status

api operation id createMerchant_v20260101 removed and replaced with createMerchant_v20260301

added the new enum value 2026-03-01 to the header request parameter X-API-Version

added the required property code to the response with the 400 status

added the required property message to the response with the 400 status

added the required property type to the response with the 400 status