Voice/instrument/part range/register

I scored a song for Mezzo-Soprano & Piano. I want to add on a second page, the range/register of the singer.
I think Anthony Hughes made a video about this, which I think I saw, and cannot find anymore.
Words I’m using for the search: voice, part, instrument, range, register, music frames.
If anyone either can share other vocabulary to use for the search, or knows how to do this in Dorico Pro 3.5, I would greatly appreciate it so I can finish this score and send it to the performers.
In any case, thank you for your time and consideration.

I think Daniel wrote a beautiful article about prefatory scores.

Here’s one from Dan Kreider : https://www.scoringnotes.com/tips/adding-reference-pitches-in-dorico/