I’m a bit confused by this (!)
What do you mean by “desktop app is vst performer 30 day trial” ? Do you mean you have installed a VST connect pro licence on your licenser ?
On your Cubase/mac you need to use the VST connect plugins
Studio pass basically takes the place of the performer app.
Set up a VST connect session as per the guide then generate the code as per this very useful guide from steve
you might not have pressed the (not very clearly labelled!) login button ? You also need to put in a (random) name