add custom column in wp admin for custom post type

function.php

// Add the custom columns to the rezept post type:
add_filter( 'manage_rezept_posts_columns', 'set_custom_edit_rezept_columns' );
function set_custom_edit_rezept_columns($columns) {
    unset($columns['date']);
    return array_merge ( $columns, array (
        'name' => __('Vor- & Nachname'),
        'email' => __('E-mail Adresse'),
        'group_of_people' => __('Personengruppe'),
        'activation_date' => __('Erstellungsdatum'),
        'recipe_status' => __('Status'),
        'date' => __('Veröffentlicht')
    ));
    
    return $columns;
}

// Add the data to the custom columns for the book post type:
add_action( 'manage_rezept_posts_custom_column' , 'custom_rezept_column', 10, 2 );
function custom_rezept_column( $column, $post_id ) {
    switch ( $column ) {

        case 'recipe_status' :
            echo get_post_meta( $post_id, 'recipe_status', true);
        break;

        case 'name':
            echo get_post_meta( $post_id, 'name', true);
        break;

        case 'email':
            echo get_post_meta( $post_id, 'email', true);
        break;

        case 'group_of_people':
            echo get_post_meta( $post_id, 'group_of_people', true);
        break;

        case 'activation_date':
            echo get_the_modified_date('l jS \of F Y h:i:s A', $post_id);
        break;

    }
}