Change the Default View for Transactions on the Sales Ledger

Click Sales Ledger then click Customers.

Then click on the Filter Options.

Then click on the Transactions Tab.

In the Transactions Tab, on the bottom left of the screen you will find Default Transaction Sort.

Change that to Transaction Date (Asc) for the oldest transaction to show first, or Transaction Date (Desc) for the latest transaction to show first.

Then click on the Clipboard, to set as default, Set needs to show Def and Save.

Then click on Apply to save the default.