From the documentation I understood that in order to change the language of the recaptcha I have to render it explicitly.

The problem is, however, that it's not really showing up, and the onload is not even called.

When I try to render it automatically it does work.

Here's the code:

In the HTML head: (I have also tried putting this at the end of the body tag)

<script src=https://www.google.com/recaptcha/api.js?onload=recaptchaCallback&render=explicit&hl=iw async defer></script>

In the HTML form:

<div id=recaptcha></div>

Javascript:

var recaptchaCallback = function() {

  console.log('recaptcha is ready'); // not showing

  grecaptcha.render(recaptcha, {

    sitekey: 'My Site Key',

    callback: function() {

      console.log('recaptcha callback');

    }

  });

}