If you have a ticket to Web Summit 2020, you can login to your ticket dashboard at: https://websummit.com/my/ws20/login using the email address your made your order with. A login link will be sent to this email.
If you weren't the person who made the order but know you have a ticket assigned to you, you can also login at https://websummit.com/my/ws20/login and view your ticket.