Your ROOT_URL in app.ini is http://159.89.207.79:3000/ but you are visiting http://9.cron.my.id:3000/mahesh/laravel-backpack/src/commit/d4f93f46b4b124001bc31dea36903a13d0ab8be5/public/packages/ckeditor/plugins/mathjax
You should set ROOT_URL correctly, otherwise the web may not work correctly.
Mahesh Sharma