JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" name="name1" id="name1" class="number" />
<input type="text" name="name2" id="name2" class="number" />
<input type="submit" name="send" id="send" class="hey" value="one" disabled />

JavaScript

$('.number').keyup(function () {
    if ($.trim(this.value) == "") {
      $('#send').prop("disabled", true);
    }
  else {
        $('#send').prop("disabled", false);
  }
});