Google assistant vs Voice Search

[maxriptin]

I'm having trouble with the forums so... I'll try this:

I have a BlackBerry KeyOne and would like to set the Google Assistant to the convenience key. However, all I can seem to do is set the old Google Now Voice Search to the key.

Google Assistant and Google Now Voice Search are different; correct?

Is there a way to set Google Assistant to a convenience key or shortcut?

If I am correct, since Google Now Voice Search is an app, it can be set to a shortcut or convenience key, but since Google Assistant is built into Nought it can't be done? That's what I'm guessing but figured I would ask here; from those that are more familiar with Android.

I've been a BlackBerry user and abuser for we'll over a decade. Did have the Priv and played around with leaked BB10 OSs w Android runtime, but didn't mess with much so still consider myself a newbie when it comes to Android.

What are your thoughts?

Thanks!