Event Calendar App lets you add what we call 'ticket links' to your events. This is a link to where people can buy tickets to your event.
They look like this:
At the moment you can't take payment for your tickets directly through Event Calendar App. You will need to use another service to actually facilitate the transaction.
A lot of our customers use eventbrite to sell their tickets and then link to their eventbrite pages with Event Calendar App. There are also many other services where you can sell tickets to your events.
If you use Shopify, it is possible to create a 'product' which is in effect tickets to your event. You can then link people to this page from your Event Calendar using this 'tickets link' feature.