JSFiddle - React, Tailwind, and code Playground

HTML

<input id="choice-file" type="file" />
<input id="submit-b" type="submit" disabled="true" />

JavaScript

$( document ).ready(function() {
	$("#choice-file").change( function() {
		if( $(this).val() ) {
			$('#submit-b').attr('disabled', false);
		} else 
			$('#submit-b').attr('disabled', true);
	} );
});