Which transaction source is used to link transaction header and line information?

You are implementing Fusion Accounting Hub for your external Accounts Receivables system. The external system sends invoices billed and cash receipts in a flat file, along with the customer classification information.
You want the accounting amounts to be tracked by customers too but you do not want to add a Customer segment to your chart of accounts.
What is the solution?

There is a business requirement to display supporting information with some text and source value at the journal line level that will vary depending on the entered amounts for the line.
What is the solution to implement this requirement?

Given the business use case:
'New Trucks' runs a fleet of trucks in a rental business In the U.S. The majority of the trucks are owned; however, In some cases, 'New Truck' may procure other trucks by renting them from third parties to their customers. When trucks are leased, the Internal source code is 'L'. When trucks are owned, the internal source code is 'O'. This identifies different accounts used for the Journal entry. Customers sign a contract to initiate the truck rental for a specified duration period. The insurance fee is included in the contract and recognized over the rental period. For maintenance of the trucks, the "New Trucks* company has a subsidiary company
'Fix Trucks' that maintains its own profit and loss entity. To track all revenue, discounts, and maintenance expenses, 'New Trucks' needs to be able to view: total maintenance fee, total outstanding receivables, rental payment discounts, and total accrued and recognized insurance fee income. 'New Trucks' and' Fix Trucks' are located in the same country and share chart-of accounts and accounting conventions.
How many ledgers are required to be set up?

A new source system has been registered into Accounting Hub Cloud. Users are actively using this new subledqer. Subsequently, the business signed up a contract with a new supplier. A new mapping value that maps suppliers with the accounts needs to be added. You make updates on the mappings in the existing mapping set rule by adding more mapping valued.
After saving the update, what is the next required action?

Given the journal:

What is the terminology that is used to identify the "Account Number', 'Original Balance' , and 'Origination Date' fields?