Embed Google PDF no Front.php

/* Mostra um PDF do google Drive embedado no Front via URL salva no Metabox do User Corrente 

USO MANUAL: 
<iframe src="LINK" width="100%" height="600px" class="pdf_gdrive" style="border:0;">

EXEMPLO: Crie um campo chamado _pdf no metabox do user OU no CPT desejado.
Adicione o trecho de código abaixo no functions.php do seu tema
Adicione o shortcode [pdf_gdrive_user field="_pdf" size="600px"]
Adicione o shortcode [pdf_gdrive_cpt field="_pdf" size="600px"]
*/

    
/* PARA USERS METABOX */
function user_pdf_google_drive_shortcode($atts) {
    
    $atts = shortcode_atts( array(        
        'field' => '',
        'size' => ''
    ), $atts, 'pdf_gdrive_user' );
    
    
    $user_id = get_current_user_id();
    $pdf = get_user_meta($user_id, $atts['field'], true);
    $new_link = str_replace('/view?usp=share_link', '/preview', $pdf);
    return '<iframe src="' . $new_link . '" width="100%" height="'.$atts['size'].'" class="pdf_gdrive" style="border:0;">';
}
add_shortcode('pdf_gdrive_user', 'user_pdf_google_drive_shortcode');
    
    
/* PARA METAFIELD DE CPTS */    
function cpt_pdf_google_drive_shortcode($atts) {
    $atts = shortcode_atts( array(
        'post_id' => get_the_ID(),
        'field' => '',
        'size' => ''
    ), $atts, 'pdf_gdrive_cpt' );
    
    $pdf = get_post_meta( $atts['post_id'], $atts['field'], true );
    $new_link = str_replace('/view?usp=share_link', '/preview', $pdf);
    return '<iframe src="' . $new_link . '" width="100%" height="'.$atts['size'].'" class="pdf_gdrive" style="border:0;">';
}
add_shortcode('pdf_gdrive_cpt', 'cpt_pdf_google_drive_shortcode');