In order to submit abstracts or to show interest in event, one has to create an account first using the registration form.
To become an attendee at the event, one has to purchase the tickets. Or to submit an abstract which requires author to pay a fee, one has to purchase tickets. That's basically the reason why Dryfta platform has separate options to register and to purchase tickets.
You have the option to either ask users to register first and then purchase a ticket, Or you can disable the registration button (from Website builder > Navigation) to let users purchase a ticket first and then system shall register them automatically and send their login credentials to them.
You also have the option to let users register and then automatically redirect them to purchase the tickets on the tickets page. Go to Form builder > Form settings and under contact registration form, enter the URL where you want users to be redirected on form submission.
Registration get users the username/password to log in to their dashboard on the event website to update their profile, purchase and download tickets and invoices, submit abstracts, submit reviews, enable public profile, disable notifications etc.