Payplus interview questions

I was tasked to make a dashboard with login&register in 3 hours using nest and Vue. I was also handed in a figma. In my years of interviews I came across few places that do this practice and maybe more seasoned devs can deliver such a thing in 3 hours but sadly I am not one of them. I estimate it would take another 3-4 hours to bring a good grade app or 2 more hours to a working poc. But the kicker is the position was for a backend Dev and I fail to see the point of tasking me to make in said time a fullstack app.