The Voucher Page is like a display page that will show the users the vouchers that they purchased. Each subscriber will have their exclusive link to their voucher page that is generated by the merge tags %sa_voucher_page% for Standalone Voucher campaigns and %voucher_page% for Voucher Directory campaigns.
If you just recently created a page that you wanted to use as a Voucher Page for your Voucher Campaign, you can edit the campaign and select it in Step 5 (Voucher)
Look for the Select Voucher Page dropdown menu and select the Voucher Page there.
Here's an example of what a voucher page can look like when accessed:
The vouchers displayed above are the ones purchased by the user.
If you are unable to select a Voucher Page in Step 5, most likely the Voucher Page that you tried to create does not have the Voucher Element. The Voucher Element is what pulls out the vouchers purchased by the customers and displays them on the Voucher Page.
To fix this, go back to the Pages section and edit the page that you created as a Voucher Page. Go to Step 2 (Properties) and click on the Voucher button in the Available Items area to add it to the Design Items.
Click Save or Submit after placing the Voucher element. Go back to the campaign and you should now be able to select the Voucher Page there.