Why is ADSBX asking for (Enter the ICAO hex ID's here) ?
Are you talking about an app that uses adsbexchange data or the main adsbexchange tracking page?
As for the main tracking page:
ADS-B Exchange - tracking thousands of aircraft
You can search by tail number as well if our database has it (it's pretty decent but not perfect).
Now details on the left will open up if something was found.
If you want to look at for example two days ago or so, click the history and it should populate the details correctly.
Then you can click through the last 1 or 2 weeks, if you find a track it has flow enable K for track labels that give you altitude / speed and a timestamp for each point in the trace.
We are aware that this is not the most user friendly interface but if you are looking for history of a specific airframe it can display very detailed data.
Compared to the VRS that was running our tracking page a year ago we have a much more stable and responsive interface that only requires a fraction of resources to run server and client side.
Let's say you're curious about this:
The Aviation Herald
The registration is JA787A, paste it in the search box and hit enter.
Open the history in the details and go back to the 20th, select the 3rd leg, this is the URL you get:
ADS-B Exchange - tracking thousands of aircraft