The “series” is really just another match. You can post and update its results similar to individual matches. The article I linked in my previous comment has a few links to the posted series you can take a look.
PS: the PractiScore Competitor app can also pull down the whole series from PractiScore web site and show it in the app. All matches for that series need to be posted to the web site. But Competitor app is optional, posted series results can be viewed on the web site.