instance attributes

hi , thank you for your plugin
i wonder how i can add multiple attributes when i use the shortcode.

i tried :
[widget name="Featured Listings | sabai" instance="show_time=true" instance="num=2"]

and

[widget name="Featured Listings | sabai" instance="show_time=true;num=2"]

and it didn’t work for me,

also i want to know how to get the classname and why i should use it ?!

https://ww.wp.xz.cn/plugins/widget-or-sidebar-per-shortcode/