Have you received a voucher for advertising on XING? If so, you can redeem it at the bottom of the settings screen for your ad:

1. Go to the menu item Promote on your event page and click on Create event ad.
2. Go to Redeem voucher and click on the link.
3. Enter the code on your voucher.

Please note: If you do not use the entire value of your voucher, you can use the remaining credit for another ad.