If you can’t find the start icon of the Piapro Studio stand alone, there is a possibility that you fail to install it. Reinstall the Piapro Studio.

The Piapro Studio plug-in is a vocal editor that you use by reading as VST plug-in or AU plug-in into the DAW software, and so there isn’t the start icon for starting it by itself.

When you use Piapro Studio plug-in, use it with starting Piapro Studio VSTi or Piapro Studio AU in the DAW software.

*Check this out for the way to read each DAW software.
*It doesn’t support AAX and RTAS plug-in, and so you can’t use it with the Protools.