How to check if dragenter has a file?

Im programming an upload website and I want to drag and drop files to upload them. Currently Im showing a prompt for the user to drop their file if he is at the right location. The problem is that also other stuff like marked text triggers the prompt. How can I check if the dragenter is with a file ?

Im using the following code:

$(document).on({
        dragenter: () => {
            //Only start new upload if old is completed
            if (!this.uploadWindowOpen) {
                $("#drop-prompt-background").fadeIn()
                $("#drop-prompt-path").text(Browser.getCurrentPath().toString())
            }
        },
        dragleave: () => {
            $("#drop-prompt-background").fadeOut()
        },
        drop: event => {
            event.preventDefault()
            $("#drop-prompt-background").hide()
            let file = event.originalEvent?.dataTransfer?.files[0]
            if (file) this.startUpload(file)
        },
        dragover: event => {
            //No file open in new tab
            event.preventDefault()
        }
})