Open your application from Studio.
Click the Create Application File button (in studio), then from Data Model menu select Table and click on Create button.
- Configure Table information. Enter a label for table (name will set automatically) then click on Submit button.
then from Control tab, if select Auto-number, then will see options, now you can set prefix, Number and Number of digits.
this setting is to set internal Id number for the records, for example in settings below id number format will be “NI000000”
Click the Submit button to save the table.