There is no specific test for this position, to review some specific app or site.
Your test would be:
1. Written review of some UX design
2. Video review of some UX design
3. UX wireframes you did for some project
Please email us these three things to firstname.lastname@example.org
It could be for three separate projects.
If you don't have all three of them, send only two.
Please note that the way you will prepare the email with these examples and the quality of the examples themselves will determine will we hire you or not.