No, it does not have a subscription. By purchasing 1 Starter Kit, you can control up to 2 doors, and for each one, you will have 5 free lifetime Virtual Remotes. You can customize, grant, and revoke these as you wish and as many times as you want, allowing you to have 5 people or users with Virtual Remotes at the same time.
If you need more Virtual Remotes, you can purchase as many Extra Virtual Remotes as you want. Each one has an annual fee ranging from 9 to 5 Euros per year, depending on the quantity you buy. It is only in this case that you would optionally pay a subscription only for those Extra Virtual Remotes for the time you desire.