How can a student leave a review after a trial lesson?

Basically what the question says. Trying to boost my profile I had an external student of mine register on Preply, book a trial lesson with me through Preply, in order to be able to leave a review afterwards as what several people have told me is that having even 1 glowing 5 star review will get the ball rolling and you will start filling up with students quickly. However, my student tells me the option to leave a review doesn't show up anywhere, he only keeps getting the push to subscribe.

As far as I knew students could leave a review on your profile if they had booked a trial lesson with you, even if the trial lesson itself didn't take place (after the date and time of the trial lesson of course).

So, what gives?