Most likely it won't fit well to the question so you gotta pick the question first.
I think because it's such a large essay such as History Extension itself, you need a focus question or you're gonna end up writing fractured arguments, like yeah you can understand how things work and how to answer your basic investigation but if dont have direction or purpose, your essay isn't going to sound very logical or have the foundations of a historiographical essay. You can have the history and why things happened but if you don't incorporate elements of history extension such as methodology or schools of histories eg empiricism/relativism/post-modernism into your essay it'll just be a historical not a historiographical essay. Good Luck tho and we can suffer together writing this 3k essay lmao but yeah its ok if you keep diverting from your original question, i kinda wanted to change mine eg i was gonna do changing historical interpetrations on Marie Antoinette's role in the French Revolution but couldnt find much on the role she played and rather i ended up searching up what people thought of her during the FR over a few centuries. It's ok if you change ur question but i think you should tell ur teacher about it lol