So yes, you want to setup a print bill button that prints the unpaid ticket, heres one way you could do it, might need to slightly alter for your needs
Your still a little vague with your explanation?
These are open tickets not customer account?
Are they multiple tickets on one customer or you want to print all open tickets for all customers?
i have already found the direction from sambapos customer account, & the problem now is how do I print customer account details layout as the attached image above, is that possible in custom report?