You need to create fiscal periods for every new year. You cannot export journal entries from Isah for a particular year if you have not created fiscal periods for that year.
The period table allows for a better connection of period numbering in Isah to period numbering in your financial application.
Enter the number of fiscal periods in which you want to divide the new year. This depends on the way your company works; consider whether you will be working monthly periods (12 accounting periods per year) or 4-week periods (13 periods per year).