After logging in, the option to delete your profile is found by clicking on your name in the top right corner of the webpage and in the app via the settings.
How it's done
On the website:
Log in, click on your name in the top right corner, and then again on your name under your profile picture on the left side of the page. Select "edit profile", scroll down, and select "delete profile".
In the app:
From the opening page, tap the hamburger menu (shown as three dashes on top of each other) in the top left and then go to Settings → Options → Delete.