In EventNook registration or ticketing URL, you can promote the event ticket sales with a discount code attached to the URL so the ticket buyers don't require to enter a discount code when they click the link.
Example: Registration with LAST2DAYS discount code
Here is how you can get the URL generation:
Go to My Events >> Manage
Go to Setting >> Site URL >> Registration Url
Enter a discount code (that's already created. If you have created a discount code, create a discount code first)