change post template in custom post type

add_filter( 'jnews_single_post_template', 'change_glossary_template', 99, 2 );
add_filter( 'theme_mod_jnews_single_blog_custom', 'change_glossary_custom_template', 99 );

function change_glossary_template( $template, $post_id ) {
    if ( 'glossary' === get_post_type( $post_id ) ) {
        $template = 'custom';
    }
    return $template;
}


function change_glossary_custom_template( $default ) {
    if ( 'glossary' === get_post_type( get_the_ID() ) ) {
        $default = 4670; /* change this with your custom post templlate ID */
    }
    return $default;
}