Ditch the patchwork nature of it, for starters.
See the Zelle "getting started" page at https://www.zellepay.com/get-started - there's no solid set of instructions because there's almost two thousand different implementations of it. Your bank's procedure may be entirely different than mine's; if your bank doesn't support it it's a different procedure alltogether.
As a result, scammers can fairly easily convince someone who's never or infrequently used it that their process (usually with a phished website posing as Zelle) is legit. The "it's a banking technology, but it's also a website and an app, maybe, it depends" thing doesn't help.