Don't find plugin

i just buy midi guitar 2 but i can’t find vst or au

Maybe you bought “MIDI Guitar for Garageband” from the appstore?
that version hasn’t got plugins, it works via virtual midi.
More info for this closely to the iOS version realted version:

If you did buy the full version, the VST and AU component are in the update download which is offered after applying the license.

i didn’t buy from App Store and when i try to update my mail is not recognize

In that case you need to contact