If you've already purchased ScoreboardLive credits, you apply one when you set up the event — you don't pay again.
Create the event under the Manage Events tab.
Fill in the event details and click Save.
After saving, the additional event tabs appear at the top, next to Details.
Open the Live Scoring tab.
Select ScoreboardLive.
Choose the option to apply your already-purchased credit to the event.
Note: unused ScoreboardLive credits expire at the end of the season