JSFiddle - React, Tailwind, and code Playground

HTML

<form name="fileForm" onchange="changed()">
  <input type="file" name="image" accept="image/*">
  <input type="submit" name="submit" disabled>
</form>

JavaScript

function changed() {
	var form = document.forms.fileForm;
	if(form.image.value.length > 0) {
  	form.submit.removeAttribute("disabled");
  } else {
  	form.submit.setAttribute("disabled", "");
  }
}