Activate pre-printed vouchers

Hi wpdev-team, i use your extension since a couple of years. It is great! For our business it would be very nice to have an option to print some vouchers (with Voucher-Code / QR-Code) in advance for offline-selling. In case a customer want to buy a voucher in our restaurant, we can activate the preprinted voucher through the QR-Code / Voucher-Code and fill it up with the specified amount and the voucher will be activated at this moment. Maybe you can change the code of the “reverse redemption” plugin a little bit, to create such a function. I would like to offer $ 300 for the development. Greetings!