Scratch cards/Punchcard/Voucher?

Is it possible to create a setup in AgencyHandy (AH) that I can use to manage my customers' credit hours?
I have customers who buy 5-10-20 hours on a β€˜punch card’/'Voucher'.
By paying in advance, they can get a small discount on my hourly rate.

When I then perform tasks for my customer, I calculate my time spent and register in AH their credit hours so that it clearly shows how many hours are left.

Would it be possible to sell a service called, for example, β€œVoucher for 20 hours”, which has β€˜20 hours remaining’ from the start?
When I perform a task, I type a prompt and the number of hours consumed, after which the system updates and clearly shows β€˜remaining hours due’. I want to offer my customers the ability to log in to the portal and follow the consumption of their hours in real time.
Optimally, the system should also be able to send a reminder to buy a new voucher when there is, for example, only 1 hour (or 0) left.