Because it's the 2012 version, it's a one-off enterprise license that we have never had to upgrade. It's a perpetual license that you install and that's it.

There are additional fees to this solution.

Check the features of the different editions on the vendor site,

https://devart.com/dbforge/sql/stusio/editions.html

for a small shop the Professional should be enough, but for data synchronization and source control you need the Enterprise edition.