One of the challenges in NaNoWriMo is that you may have the start of your novel set, most of the plot points on an outline, but what about the ending? Do you know where this thing ends?
Write your ending first.
Why not? Take a writing session and write the last scene, chapter, or maybe the last two or three chapters. Take your story to the end to see what happens, then start from the beginning.
You might discover that the plot outline you carefully planned out needs to be shifted around, the journey changed as you’ve decided to take this in a new direction. Or that you will have to add characters or remove them, or change other parts of the story to make it tie up with the ending you’ve written.
You can always edit and change the ending later, but knowing your destination might help you get there sooner, and enjoy the journey better.