Specific ICS url for category

In my case I have multiple event categories. I would like to make a specific ics url for each category. I tried a lot of url variations, but unfortunately it does not work.

https://wordpress.local/events.ics (this works fine, and show all events)
https://wordpress.local/events.ics#_category-1 (this url shows also all events)
https://wordpress.local/events/categories/category-1/events.ics (this url shows nothing)

Please can anybody help me how the url should be to show the category events only?