how to use plugin for sub category

That URL doesn’t work because (as it is explained in the help dialogue when you hover over the question mark icon next to permalink) you can only use one wildcard. What you want is the fuzzy URL matching feature. Check also affect children on the plugin filter and enter the permalink as https://www.kiransboutique.com/product-category/. You must have fuzzy url matching enabled on the Plugin Organizer settings page.