Hello. You didn't say which novel this question is referring to. This makes it impossible for this question to be answered, but I can help by showing you what a primary source is and showing you how to find it in the novel.
Primary source is a document that reports the events of a historic event. However, this document was created at the time that this event is taking place.
In this case, the novel you are studying to answer that question, will bring a primary source when showing a document about one of the historical events mentioned above, at the time when these events occur.
For you to understand better, imagine that you are reading a novel where one of the characters is a doctor and is reporting in a diary the operation of a hospital during the coronavirus pandemic. In this case, the doctor's diary is a primary source to which the novel is referencing.