Yamaha Prologue offer- Cubase AI7

Have an activation code for Prologue that was included with my MOXF6.
The download URL was incorrect however, managed to download the Prologue_Synth_Installer.exe (v1.3.1.97) from Yamaha website MOX download page.
When I attempt to install Prologue, an error message pops up saying I need to install Cubase AI5
I have installed AI6 (previously) & AI7.
I read that Prologue is only included in Elements and higher and not in AI versions.

I went in and entered the activation code in my eLCC, it came up with the Prologue key but then I received an email with a new activation code.
Am I able to get Prologue as a VST somehow and what is the correct procedure

Update -
I also entered the activation code for the YC-3B plug-in in my eLCC.
I have since started AI7 and when I went to insert an Instrument Track both the Prologue and YC-3B were in the dropdown list of VST Instruments along with the HALion Sonic SE.
I then spent time trying out both instruments and their sounds.
Perhaps detailed instructions should also be included… :confused: