How to get Drupal 8 View to Accept Parameter as argument?
You can do it with a contextual filter. In the "Configure contextual filter" menu select "Provide default value". For type choose Raw value from url.

There is more info on contextual filters in this article.

http://redcrackle.com/blog/adding-contextual-filter-view-drupal-8

If you are using taxonomies and want to use the name instead of id in the url you need to setup the relationships first and use name as the contextual filter.