Flavored seltzer before havdalah

Is it permitted to have seltzer water flavored with essence (like La Croix or Polar) after shkia motzei shabbos before havdalah? I know water is permitted, but tasting something is forbidden. Moshe sweetened the water at Mara with a branch, and that was still water

Yes, soda is permitted

אסור לאכול שום דבר או אפילו לשתות יין או שאר משקין חוץ ממים משתחשך עד שיבדיל
What about this mechaber in 299 ,1
That explicitly writes shar mashkin

The Rav holds soda is water. For that matter so is coffee and tea. They are in “essence” all water with flavoring, as opposed to juices, milk and the like.