There are three DC webcomics I know about:
(All ongoing, free-to-read series on WEBTOON.)
It's not clear to me where they stand in relation to other DC works, or even in relation to each other. They clearly reference the greater DC body of works, but what's canon and what's just inspiration?
There are some possible connections within the series. Vixen (and friends) appeared in WFA. Batman appeared in V:NYC, and another episode (featuring Teen Titans Beast Boy and Raven) name dropped Robin. However, these episodes give me the impression that the series have different timelines and represent different canons. Batman in V:NYC, for example, seemed to be a fairly generic portrayal, with little to tie him to his depiction in WFA.
(I can't comment much on Zatanna since I haven't read much. But the premise of the series makes me think there's not many opportunities for crossovers.)
So what's canon?