Creates an execution order routed directly to a custodian for the given parent order.

Requirements:

• The parent order must be in the pending_execution or partially_filled state.
• amount.type must be shares or notional. par is not supported on this endpoint.
• limit_price, when provided, is interpreted as price per share.
• Multiple execution orders can be created for a single order provided that the sum of their open quantities does not exceed the open quantity of the order.

Once submitted, you will receive one of the following events:

• A system_update event with an event_type of execution_order_request that indicates the request was received.
• A system_update event with an event_type of execution_order_reject if the request fails.
• An order_update event with an event_type of execution_order_create if the request succeeds & is pending execution.

All events include the execution_order_id.