您只需将过滤器添加到the_content 就像这样：

function wpse_337486( $content ) {

    if ( is_single() ) {

        // Get the current post.
        global $post;

        // Get all post tags. Get only their names.
        $tags = wp_get_post_tags($post->ID, [\'fields\' => \'names\']);

        // Append post tags to content.
        $content = $content . \' \' . implode(\' \', $tags);
    }

    return $content;
}

add_filter( \'the_content\', \'wpse_337486\' );