There are three components which will help you.

The epigraph, the numbers on page 44, and the door.

The pictures on the door represent pages.

The numbers on page 44 represent three different pages.

Take a look at the door. The circle on each page points to the small box in the page. What do you think that means?

The epigraph mentions "locates not once but two times." The quote is referencing the numbers.

Each number first helps locate a page. How do you think they can help locate a second thing?

You are not trying to find a letter.

You are looking for three words.