You would have to use some participant data with some checks at the front of the flow. I would use the reusable tasks that allow you to flow into that and back to the point of exit. The other and probably better is to use a Common Module to act as an external flow in line with the call flow.
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Robert Wakefield-Carl
TTEC Digital, LLC fka Avtex Solutions, LLC
Contact Center Innovation Architect
https://www.ttecDigital.comhttps://RobertWC.Blogspot.com------------------------------