Explanation
The object that the user should navigate to to review credit card payment data for a specific Order is Order Payment Summary. An Order Payment Summary is a record that represents a payment made for an order or part of an order. An Order Payment Summary has a lookup relationship to both Order Summary and Invoice objects, and it contains information such as the payment amount, method, status, etc. Verified References:https://help.salesforce.com/s/articleView?id=sf.order_management_order_payment_summary.htm&t

The type of relationship that exists between FulfillmentOrder and Order Delivery Method is Lookup (OrderDelivery Method). A Lookup field is a type of custom field that creates a relationship between two objects, but does not support rollup summary fields. In this case, a FulfillmentOrder has a Lookup field named Order Delivery Method that references an Order Delivery Method record. An Order Delivery Method is a record that represents a delivery option for fulfilling orders, such as standard shipping, express shipping, in- store pickup, etc. An Order Delivery Method can have many FulfillmentOrders associated with it, but a FulfillmentOrder can only have one Order Delivery Method. Verified References: https://help.salesforce.com/s
/articleView?id=sf.custom_field_types.htm&type=5https://help.salesforce.com/s/articleView?id=sf.
order_management_order_delivery_method.htm&type=5

Explanation
Order Allocation should work on Order Items in Awaiting Allocation status. This status indicates that the Order Item has been confirmed by the customer and is ready to be allocated to a Fulfillment Order based on routing rules and inventory availability. Verified References:https://help.salesforce.com/s/articleView?id=sf.order_management_order_item_status.htm&type=5

Three things that the administrator can do to get more details for debugging when encountering an unhandled fault error are:
Create a fault connector. A fault connector is a special type of connector that handles errors thatoccur in a flow element, such as an assignment, a loop, or an action. A fault connector can route the flow to another element or end the flow with an error message.
Add a Display Text component which includes {! SFIow.FaultMessage}. A Display Text component is a screen component that displays text on a screen element in a flow. The {! SFIow.FaultMessage} is a system variable that contains information about the error that occurred in the flow, such as the element name, error type, and error message.
Create an error connector. An error connector is a special type of connector that handles errors that occur in a screen element, such as invalid user input or required fields beingleft blank. An error connector can route the flow to another screen element or endthe flow with an error message.
Verified References: https://help.salesforce.com/s/articleView?id=sf.flow_ref_elements_connector_fault.
htm&type=5 https://help.salesforce.com/s/articleView?id=sf.
flow_ref_elements_screen_component_display_text.htm&type=5 https://help.salesforce.com/s/articleView?
id=sf.flow_ref_elements_connector_error.htm&type=5