Add default Category or Tags to a CPT

<?php
add_filter( 'pre_get_posts', 'my_cptui_add_post_types_to_archives' );

function my_cptui_add_post_types_to_archives( $query ) {
    // We do not want unintended consequences.
    if ( is_admin() || ! $query->is_main_query() ) {
        return;
    }

    if ( is_category() || is_tag() && empty( $query->query_vars['suppress_filters'] ) ) {

        // REPLACE THESE SLUGS WITH THE POST TYPES YOU WANT TO INCLUDE.
        $cptui_post_types = array( 'custom-post-type');

        $query->set(
            'post_type',
            array_merge(
                array( 'post' ),
                $cptui_post_types
            )
        );
    }
}
?>