Add new argument in order by option

I am using widget-reloaded plugin and i have a function which count post views. I have to sort categories according to post-views, the post views give total views per post and query like “select category from wp_category order by post_views“;, Either i can use this query directly in wp_list_categories and pass other params like exclude params etc but that can be done manually. I tried plugin file and add option in form but didn’t found how to activate new argument in form

https://www.ads-software.com/plugins/widgets-reloaded/