Magic Leap OS 1.2.0 adds a QR Reader app, accessible from the app launcher, or via a shortcut in the built-in browser.
Launching the app will show a viewfinder interface similar to the capture feature. To start the process, look at the QR code. When the QR code is in the area of the viewfinder, it will be highlighted yellow as the code is read.
Upon successfully reading the code, a pop-up will appear asking if you want to open the link in the browser.