If you're trying to launch your host application or DAW and PhoenixVerb is prompting for authorization, you should be able to enter your activation code delivered to your upon purchase.
If you're unable to complete this, it's possible you have the Surround version of PhoenixVerb instead of the normal Stereo version. You can install PhoenixVerb from your Product Downloads.
If you need to uninstall any Exponential Audio product you don't own, you can see our article on how to uninstall.