The voucher system is a simple web system with which vouchers, coupons, vouchers, etc. can be administered and redeemed. The structure is really very simple - to redeem the admin user name and password together with the ID to be redeemed are entered and sent, so there is no login. Sending vouchers via GET is also possible, but not very secure (I used this to redeem vouchers with the help of a barcode scanner app on my mobile phone, which could only execute GET requests). The system runs on PHP, the vouchers are stored in a MySQL database.