Drag and Drop File Upload Question

Being new to Javascript, I am using Joe Zim’s Drag and Drop feature. You can see it here: https://codepen.io/joezimjs/pen/yPWQbd
It works fine as is. My problem is it uploads the file immediately when you drag or drop the file. I want to incorporate this into an existing form and have the file uploaded at the same time all of the other form input are submitted. Can this be done?
Thanks and appreciate the responses.