The first few prints of EZdrummer did not include all formats. RTAS, required for ProTools users, is available as a download from the support page http://www.ezdrummer.com/support/. Creation of a customer account is all that is required to access the update.
If you have the latest version installed, please make sure you are trying to instantiate EZdrummer on a stereo track (an Instrument track is recommended). On choosing the ProTools ‘New Track’ command ensure that you change the default track settings from Mono to Stereo.
EZdrummer will not appear as an insert on a Mono track.