在文章存在目录的情况下出现关于wpjam-toc.php的Notice提示

问题描述：
当文章内容中出现“X级标题”时，在文章生成目录的情况下会出现如附件图片的提示，以下为提示的文字版

Notice: Undefined offset: 3 in /XXXXXX/wp-content/plugins/wpjam-basic/extends/wpjam-toc.php on line 34

Notice: Undefined offset: 3 in /XXXXXX/wp-content/plugins/wpjam-basic/extends/wpjam-toc.php on line 36

Notice: Undefined offset: 3 in /XXXXXX/wp-content/plugins/wpjam-basic/extends/wpjam-toc.php on line 34

Notice: Undefined offset: 3 in /XXXXXX/wp-content/plugins/wpjam-basic/extends/wpjam-toc.php on line 36

且文章目录不能正常生成，如果有若干目录，只能生成一个链接向wpjam官方博客的超链接。

望解决，谢谢。