The Journyx login screen lists the version in the bottom corner of the screen. Depending on the version it can be either the left side or the right side.
For example, this is showing this is Journyx version 12.0.2:
And an example of Journyx 11.5.2:
And, finally, an example of Journyx 9.5m1:
System Information Page
As an Administrator head to the System Information page. This can be under Settings -> System Settings -> System Information, or Configuration -> System Settings -> System Information, depending on which version of Journyx you are running.
On the resulting page you will have a list of details about the current Journyx installation. The first line will be the Version.