Hello,
this worked for me:
Open the file es-loadwidget.php (wp-content/plugins/email-subscribers/classes) and delete the PHP call on line 43 and add this:
$es .= '<div><input onchange="this.setCustomValidity(validity.valueMissing ? \'I accept the terms and conditions\' : \'\');" id="field_terms" type="checkbox" required name="terms"> <span>I accept the <a href="https://yourlink" rel="nofollow" target="_blank"> terms and conditions</a></span></div>';
Note the backshlashes in “onchange”.
However, a registered hook for future updates would be much appreciated!
