Unfortunately, at this time Relay does not integrate with Zelle. We're working hard to add support for Zelle but don't yet have a timeline for when this may be available.
In case your business partners cannot be paid through ACH, Wire, or check, we're happy to recommend PayPal or Melio.
An article to connect your Relay account to PayPal can be found here.
More information about the various platforms with which Relay can connect is available here.