Redirect to form after failed validation

Hi Steffen,

A little bit tricky, you can add the redirect function when validating with the hook rwmb_frontend_validate. Like this

add_filter( 'rwmb_frontend_validate', function( $validate, $config ) {
    if ( empty( $_POST['field_id'] ) ) {
        wp_redirect( 'https://facebook.com' );
        die;
    }
    return $validate;
}, 10, 2 );

Hi,

Currently, it is not possible to redirect to a URL if the validation is not passed. I will inform the development team to explore the possibility.