What is the "character monologue" of Scout in To Kill a Mockingbird?I'm supposed to write the character monologue for Scout but I cannot find it in...

There is not a "character monologue" of Scout presented in
the novel, other than in the form of her narration of the book itself.  If you've been
given the assignment to write a character monologue for Scout, this is more of a
creative writing assignment than something you can "find" in the
novel.

A "monologue" is a term used in drama to denote one
character speaking a particularly lengthy speech.  It is very often done alone on stage
and usually reveals the characters inner thoughts and emotions about an event in the
play.  If you are writing a character monologue for Scout, depending on the specifics of
the requirement, my advice would be two choose one particularly dramatic or humorous
scene in the book (such as the mob scene or Scout's first day of school) and have Scout
present what happened along with her reactions.  Remember, her narration of the book
comes from her adult point-of-view, but maintains her childhood memories of events,
including her innocence and ignorance of many things.  A creative monologue might choose
either a fully adult Scout's presentation, or the young Scout's interpretation without
the eyes (and voice) of wisdom behind them.