JSFiddle - React, Tailwind, and code Playground

HTML

<form method="post">
    <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 />
</form>

JavaScript

$(document).ready(function () {
    $('.number').on('keyup blur input', function () {
        $('#send').prop("disabled", !$.trim(this.value));
    });
});