Firebase is a great platform provided by Google to build realtime applications. Developers no need to implement socket connection to get database changes every time and refresh the data on page. Firebase does it automatically. As soon as a data is changed in Firebase, it generates event and the connected clients automatically gets updated with the changed data. Firebase has saved lot of time of developers.
I have prepare a short code showing way to download the file from Firebase Storage. I have injected the downloaded URL directly into the img tag. You can pass that URL to anchor tag and the browser will download the file automatically.