Download the app or login via doorlist.app and sign in using your name and phone number; these cannot be changed later, so make sure they are right the first time
Create an event on the app using the + in the dock or at doorlist.app/create
Check your organizations in the Profile tab of the app
Check your upcoming events in the Profile tab or in the Calendar tab of the app or in your feed on doorlist.app
Use your personalized QR code (“My QR Code”) available via app or doorlist.app to scan into your events