You can easily upgrade your contest when posting it.
You may also do so while your contest is open for entries:
Go to your contest’s page.
Click the Upgrade tab.
Tick the upgrades that you need. The total cost will be displayed at the bottom right part of the list.
The NDA (Non-Disclosure Agreement) and Urgent upgrades may only be applied when starting a contest.
Click Upgrade Contest. You will be prompted to fund the upgrades. Once completed, the upgrades you picked will be applied.