Your attendees will be able to buy raffle tickets from the event's webpage. Once they are online, they will select View Items from the top right corner of the event site.
This will display a screen showing all of your available items for sale, to include raffle tickets.
Once they select the raffle ticket option, they will be able to enter their desired quantity and add it to their cart.
From there, your attendees will Submit their payment to purchase their raffle ticket! If the attendee does not yet have a method of payment attached to their profile, they will be prompted to add a card at this time. If an attendee has ApplePay or GooglePay set up on the device they are using, there will be a choice to use these features as well.
As an event organizer, you also have the control to make raffle tickets a part of your attendees Ticketing options as well. From your Manager Portal, navigate to the Items tab to find the raffle tickets.
From here you can scroll through the item's Advanced Options and enable Show in Event Ticketing.
Once this is enabled, your attendees will also be able to buy raffle tickets from the Regisration section of your event site. Please see below for a screenshot of how this will appear within your event site.