To add a parking voucher that can be sent to the Customer at the time of making a booking, go to the Settings – Parking Lots tab, then select the parking lot for which you plan to create a voucher. The next step is to select the Voucher tab.
You can use the available template by clicking the envelope labelled templates, or design your own voucher.

After clicking the purple "show" button, you can preview what the voucher will look like in its final version.