First of all, please make sure you have the latest Superior version installed on your computer. It is available as a download from Dashboard section of your MY ACCOUNT.
If you have the latest version installed and you still can’t find Superior among your plug-ins, check that you are trying to instantiate Superior on a stereo track (an Instrument track is recommended). Specifically, on choosing the ProTools ‘New Track’ command, ensure that you change the default track settings from Mono to Stereo as Superior will not appear as an insert on a Mono track. This is expected and normal.