Hi,
Go to UsersWP->General->Author box->Author box Content (bootstrap) and put [#user_registered#] in the content where you need and then try adding following code in functions.php file of your currently active theme or via Code Snippets plugin and let me know if it works or not:
add_filter('uwp_author_box_output', 'uwp_author_box_output_cb', 10, 1);
function uwp_author_box_output_cb($output){
global $post;
if(!$post){
return $output;
}
$author_id = $post->post_author;
$user = get_user_by('id', $author_id);
$key = '[#user_registered#]';
$value = date("M Y", strtotime($user->user_registered));
$output = str_replace( $key, $value, $output );
return $output;
}
This is the way to create and use your own custom tag for the author box. You will find more tags you can use in your author box content.
Regards,
Patrik