How do I look up an Itinerary in the Agent Advantage console?

First, log into the Agent Advantage tool:
https://www.flightstats.com/itinerary/home.do

Hover your cursor over the Itinerary tab and select "Itinerary Search" in the drop down list.

Itinerary Search:
https://www.flightstats.com/itinerary/Itinerary/itinerarySearch.do?

To look up all itineraries on a given date, select a departure date and click Search.

To look up all itineraries associated with a traveler, enter their email address or phone number and click Search.

To look up all itineraries associated with a group, enter the Itinerary Group Name, select a departure date and click Search.

To look up a specific trip, enter the Record Locator, PNR, or Trip Reference ID in the Record Locator field and click Search.

If you do not know the Record Locator, PNR or Trip Reference Number, you can search by Airline, Flight Number, and Departure Date to obtain an entire list of trips associated with that flight.

What is a Trip Reference Number?
https://helpdesk.cirium.com/hc/en-us/articles/360030470972-What-is-a-Trip-Reference-Number-