You should put a midiformat after the makenote.
Check the help file for vst~ -and Check midi tutorial 2
‘midievent’ is correct but you need to add 144 ‘status/command byte which tells it that its a midi note before note info. Also your makenote has no duration set.
I added 144 after "midievent"message and then the sound appeard.
I’m going to see midi Tutorial 2 from now on.
Thank you very much!