It was released on an Amiga Format cover disk.
Check here, it looks like you can download it:
https://amr.abime.net/issue_189_coverdisks(Haven't tried myself, I already have the disk from back then.)
Edit: Wait, maybe that's not the Pro version, it's just called Vista on the page and in the mag. But I'm almost sure the Pro version was also on some cover disk. Maybe someone else knows.
Best regards,
Niels