Hello Alan,
Thanks for your patience while we got back to you.
The minimum specs for Tonex is 10.15 or above, while older versions may have installed it was not ever supported.
If you had it previously installed then you can still access it but again its not officially supported on 10.14 or below.
Go to your My Products > (Product) > Past Releases > You can manually download and install from here.
IK User Area - https://www.ikmultimedia.com/userarea/
Here you can get software updates, drivers, sounds, manuals.