With my P3A data went straight to AirData when using Litchi.  Now with my new Mavic air 2, i can not figure out how to get the data to send to AirData.  Is there an automatic way using DJI-Fly?  I uploaded DJI Assistant 2 fo rthe Mavic and when i plug in the USB cable, it searches for flight data and finds none (Have taken just 4 flights).  How do i see the flight data?  

You need to connect your DJI account with AirData and it will work.  Do that in Airdata.  One caution though, is that there seems to be a glitch with having auto-sync on in the fly app, in that it will sync a partial flight and that will move over to AirData.  DJI will have the full flight (it seems to re-sync), but Airdata never gets the full data and you have to upload manually.  For now, the work around is turn off synching, fly, then turn synching back on.

I tried to upload manually and the DJI Assistant 2 comes back saying it is can't read the data.  It must be there.  

No reason to use DJI Assistant.  You can upload the logs right from your device by browsing to Airdata.com, and uploading the file.

Fantastic!  It worked perfectly.  I had no idea the flight logs live on my phone.  I assumed they loved on the drone.  I uploaded them and now can analyze route flight. I dump them into and excel spreadsheet to watch battery cell behavior and lots more.  
Thank you for your comment.  

Hello there bob37. I am sorry for the trouble and thank you for reaching out. I hope that you will get the information and best feed back from our DJI co pilots who had used the Airdata application. Thank you and have a safe flight always.