Flow Builder Challenge

When I try to finalize the challenge for this module:

https://trailhead.salesforce.com/content/learn/modules/data-and-actions-in-flows/communicate-with-users-flow?trail_id=build-flows-with-flow-builder&trailmix_creator_id=samlg&trailmix_slug=my-trailmix

I get the following message

I cannot seem to figure out how to solve it.

Any help would be appreciated.