If I understand you correctly, you have Finale PrintMusic v2014, not the “full Finale” - right?

And you are trying to insert a new, blank page (= without music notation) in the middle of the document - right?

The manual you are quoting (linking to), is the manual for the “full Finale”, not the manual for PrintMusic.

As Far As I Know, PrintMusic can not do it.

Upgrade to the “full Finale”, and you can do it.

Or, do you want to insert a page that will have music on it?

Here's the PrintMusic 2014 Manual

https://usermanuals.finalemusic.com/PrintMusic2014Win/PrintMusic.htm 

>And you are trying to insert a new, blank page (= without music notation) in the middle of the document - right?<

>Or, do you want to insert a page that will have music on it?<

By focusing on what you want to accomplish, there are workarounds for either of the above. We have to know which you are trying to do.