Hey @Catherine Grant52! First, I'd double check that the subscriber is actually in ConvertKit by searching their email address on the subscribers page54. Then, from their subscriber profile53, confirm that the sequence shows up on the sequences tab.
If the subscriber isn't in ConvertKit and/or the sequence is not showing on their profile, then the issue might be with Zapier not communicating with ConvertKit properly. In that case, Zapier's support team would be best-equipped to help troubleshoot that side of things.
If the subscriber is in ConvertKit and the sequence is showing up on their profile, then the next step would be to check that none of the factors in this troubleshooting guide could be preventing that email sequence from sending: Why Isn't My Sequence Sending?84
But if that doesn't resolve it, please feel free to reach out to our team at email@example.com (or via the in-app messenger in your account) with a description of the issue, name of the sequence, and subscriber's email address. One of our Product Specialists will be able to take a look at your account and help troubleshoot further from there! ☺️