How to pass file from JS to Python eel

Question

I am having the user input a file for the frontend. I want to grab the file from the html with js and pass it to Python eel to do calculations with it. How can I make this happen?

html

<input type="file" id="upload-file">

JS

let uploadedFile = document.getElementById("upload-file").files;

eel.read_file(uploadedFile);

python ell main.py

@eel.expose
def read_file(uploaded_file):
    print(uploaded_file)    # outputs: uploaded_file
    # do something with the file