Once your voucher is purchased, it will appear in your voucher 'Vault'. This is located at the top of the Vouchers tab. There are two sections: 'My vouchers', which contains your active vouchers, and 'Archive', which contains your used and expired vouchers.
In the 'vouchers' section, if you select a voucher, it will take you to the information page, where you can use the link to the merchant store in order to check remaining balance along with a how to use guide and conditions.
If your voucher can be used in-store, you will also see a bar code that you can use to redeem it physically.
The same information is also available to you in an email that will be sent to your registered email or in the email of the person you are buying a voucher for, once they have claimed it through the link you share.