Bookings : add a link in the description of a service

Hello,

I will use Bookings for the registration of attendees to some courses. In this case, each course is a service. In the description, I would like to add a link so the attendees can read/download a pdf with the detailed informations of this course.

Is it possible to add a link? I tried to add it as html tag, but the code is written as a text and not as an url to click.