The Google Assistant is a voice assistant service from Google. The assistant works across devices such as a Google Phone (e.g., a Pixel) or a Google Home device. Google does not make the Google Assistant available to EDU accounts like Michigan Tech. This is because the Google Assistant relies in part on Google's "Web and App activity" function, and this function is disabled for Education accounts per the Student Privacy Pledge Google has signed.
This means that the Google Assistant will not work with your Google mtu.edu account but can be used with another non-EDU Google account of your choice.
For detailed information about this, you may refer to the Google for Education's Privacy & Security page and the Student Privacy Pledge web site.