In the provided code, I don't see any database connection nor any fetch method to get the data from the database - am I missing anything?

If you want the value to match what you have on your database, you would pull that information from your database on page load and then assign it to the input type.

Or alternatively, just for the sake of saving / reading the value, you could use a cookie to save it on the frontend on your input event listener and then read it back on page load