Help kegging and flavoring

In the process of making kombucha. When the kombucha will be ready I plan on putting in a corny keg and carbonat with CO2 ( as I do with beer ) the question is: when and how to add flavors ? Like maple and blueberry ?
What quantity ? Do I need a second fermentation ( I don't need the CO2)

Thanks in advance

I've been looking at Kombucha recipes and culture for a while and have never seen it kegged, or injected with CO2. It self-carbonates, and people pretty much drink it right away, or put it in a few bottles in the refrigerator. I kind of think this is because the yeast (in the SCOBY) needs air in order to not make alcohol. In a wine or beer situation, you would have the yeasted mixture in a carboy with an air lock on top to keep air out. Kombucha is brewed with a piece of cloth/coffee filter on the top to allow air in. So it is a difference between aerobic and anaerobic brewing. Here is a thread from 2010 https://www.homebrewtalk.com/showthread.php?t=210370

Flavors are often put in before capping the bottles.

I'd be interested to see what happens with this.