reCAPTCHA v3 or v2? code example

Example: recaptcha v3

<script src='https://www.google.com/recaptcha/api.js?render=CLAVE_SITIO_WEB'> 
</script>
<script>
    grecaptcha.ready(function() {
    grecaptcha.execute('CLAVE_SITIO_WEB', {action: 'formulario'})
    .then(function(token) {
    var recaptchaResponse = document.getElementById('recaptchaResponse');
    recaptchaResponse.value = token;
    });});
</script>