JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
    <body>
        <form id="form">
            <input name="input-data"/>
            <button type="submit" name="action" value="first">Submit</button>
            <button type="submit" name="action" value="second">Another Submit</button>
        </form>

        <script>
            function handleSubmit(event) {
                event.preventDefault(); // don't have the browser refresh on submit
                const formData = new FormData(event.target);
                for (var pair of formData.entries()) {
                    console.log(pair[0]+ ' ==> ' + pair[1]);
                }
            }

            const form = document.getElementById('form');
            form.addEventListener('submit', handleSubmit);
        </script>
    </body>
</html>