Hi there,
Thanks for reaching out!
Since you’re using WooCommerce, the best way to do this would be to create coupons within Woo that you could then send out to your users.
You could create separate free tickets, but hiding them from the front end would require a customization. If you’d like to go this route, I would recommend taking a look at our themer’s guide, which has some great info on customizing our plugins.
Let me know how that works for you and if you have any questions!
Thanks,
Jennifer