Hi, it appears that Vouchers first appeared in version 1.3b3 and then a patch was carried out in version 1.3b4. Before upgrading to the latest 1.3b15 version you need to upgrade to 1.3b7.
I'm running the generic-pc image so downloaded 1.3b7 using the below link
http://m0n0.ch/wall/downloads-local/generic-pc-1.3b7.img....I then upgraded this to the latest firmware 1.3b15 using the following link
http://m0n0.ch/wall/download.php?file=generic-pc-1.3b15.imgTo update from your current version of Firmware you need to access the webgui using
http://192.168.1.1 and go to System\Firmware or click
http://192.168.1.1/system_firmware.phpClick the "Enable Firmware Upload" button, browse for the 1.3b7.img file and click "Upgrade Firmware" and after m0n0wall restarts you should now see a Voucher tab under Captive Portal.
You can just stick with version 1.3b7 if you like as this has Voucher support or you can go back to the Upgrade Firmware section and upgrade to 1.3b15.
I started with m0n0wall version 1.2b7 so for some reason I had to upgrade to the latest Non Beta version of 1.235 (
http://m0n0.ch/wall/download.php?file=generic-pc-1.235.img) first before going to 1.3b7 then 1.3b15 as it would let me go from 1.2b7 to 1.3b7.
I hope this helps.
Topic: VOUCHER IMPLEMENTATION