The "Use default ledger" option will automatically select the correct ledger on repeating invoice templates for a property.

After setting up ledgers for a property and assigning accounts to each ledger, set the "Use Default Ledger" to YES to automatically populate the ledger field when invoices are generated.

If the "Use default Ledger" setting is set to YES, changing the ledger settings on a property will update the selected ledgers for invoices generated from that point on.

See here for how to set up accounts against a property's ledgers.