On Demand Invoice?

Yes... From the Operations screen, go to invoice under billing... when the next screen comes up go to manually create  invoice.. On the next screen highlight the tenant and hit next. if the tenant already has a balance, the charges will be listed there and you simply highlight each charge and hit the add to invoice tab....Once you move the charges down, then you can preview the invoice and print.

If you want to create an on demand invoice for future charges.....follow the same steps... when you get to the invoice screen no charges will be listed.... Go to the adjust charges under ledger on the right.... add the future charges to the account and hit ok... then when you return to the screen the next month's rent/charges will show and you can move it down to the invoice... preview and print.