font selection for ipad ios scrivener

I followed the using fonts across platforms and added fonts folder for dropbox today.

I have a project already started prior to doing this as I noticed the font’s kept changing when I added a new draft under that project My hopes are to use the same font

How do I select a font - say courier that is in dropbox fonts folder now on my project folder on my ipad pro scrivener?

and how do I change the font on my other drafts that are in the project folder?

I’m a newbie to scrivener for ios ipad
thanks
Rose