I just applied via their website. I had to fill out my introduction. That was all actually. I passed, and I am currently working as their freelance editor.
The interview is essentially just the online editing test, where you edit two or more of the essay samples provided. Then, when hired, you complete the process and receive information about how their system works.
Interview questions [1]
Question 1
Basic qualifications state “enrolled in or completed a graduate program.”