There is no test for this position.
Simply send 3 links of Webflow websites you did to firstname.lastname@example.org
If you did only 1 good website, send only that one. That's better than send 3 average one.
If you did a tons of them, you can send 3 most interesting one and write simple description why you pick exactly these.
Your job would be to pixel-perfect convert websites from Figma/Sketch/PSD/XD into Webflow.