Have you reviewed the Qualtrics Support page at https://www.qualtrics.com/support/survey-platform/survey-module/survey-flow/advanced-elements/authenticator/authenticator-overview/#SettingUpAnAuthenticator?

https://community.qualtrics.com/XMcommunity/discussion/comment/41098#Comment_41098Yes, Matthew. I followed the instruction and set up an Authenticator which seems to work just well. But the instruction doesn't cover how to pull data from a built-up contact list. And that is where the problem occurs. As you can see, this contact list I am planning to use obviously has embedded data.
But when I selected it in my workflow, it said "The selected panel has no embedded data."
Could you help me fix this? Thanks a lot.

It looks like you're following the steps correctly in the second screen shot. It's hard to tell for sure from the first screen shot, but the problem might be that there are no embedded data fields added to the contact list. Do you have XM Directory? The contact view in the first screen shot looks different from what I see for contacts in XMD, where the Embedded Data fields that are associated with the contact list are found in the lower right. Or is it possible that you're using a trial account?

https://community.qualtrics.com/XMcommunity/discussion/comment/41119#Comment_41119I don't seem to have XM Directory.
And I am not sure if my account is a trial one either, for there's no any badge in account setting. How do I tell? Or should I contact my admin to check? Thanks.

If you have a Qualtrics admin, you should check with them about your account type and permissions, and whether your organization's license has XMD. Unfortunately, now that I have XMD, I can't remember or test this under the conditions of your account.