If you have installed using Arturia Software Center (ASC), then you can find the path in ASCs preferences.
If you have installed using an individual installer, then it's on the path you set during the install.
But as i suggested, then you can also use Windows search function. It's a good tool for different situations.
If you have'nt set any paths yourself, then perhaps you'll find the VST on one of the paths you can find here:
https://helpcenter.steinberg.de/hc/en-us/articles/115000177084-VST-plug-in-locations-on-WindowsI can't remenber Arturias default path, as i set my own, but it's one in that article i think.
The VST3 have the standard location, that you also can see in the article.
Be sure your DAW read the correct locations.
Plugins should not change path, unless you install it on another location.
If it's still missing, then have you unchecked it to be installed?