If the guy you bought the MP from synced all his flights between GO4 & DJI servers ... and if you can get hold of his DJI account login, then you can have them synced up on your Airdata (if more then 100 logs you need a paid Airdata subscription).
Or if the guy still have the logs in his phone/saved on computer you could ask him load them off & hand all the .TXT logs over to you ... then you need to manually upload all to Airdata.
In what ever alternative the go to guy is the seller ... if not cooperative, the logs are deleted from his phone or not synced with DJI it will be impossible to get hold of that .TXT log history.
As you have a MP you can though still get hold of the Aircraft stored .DAT logs ...
Aircraft DAT files
These contain the most comprehensive data, logged at the highest rates. A DAT file is started at aircraft power up and continued until power down, and includes numerous boot sequence, sensor calibration and diagnostic data in the flight event stream. There are also hundreds of data fields, many of which are flags or diagnostic computations of unknown types, probably understood only by DJI. However, among these are the raw and processed sensor data and the IMU solution for aircraft attitude, position, velocity and heading, together with battery and motor data, recorded at rates varying from 5 Hz to 200 Hz. These data are very valuable for diagnosing flight control problems. The files exist independent of the mobile device control app being used.
Unfortunately, on recent DJI models (Mavic Air, Mavic 2 and Mavic Mini) the decryption keys are hidden, and so those are not readable except by DJI.
This is how:
Aircraft DAT files
These are only readable from the Mavic Pro and Mavic Pro Platinum (plus Phantom 3, Inspire 1, Phantom 4, Phantom 4 Pro, Inspire 2, Inspire 2 Pro, Matrice 100, Matrice 200, Matrice 600, and Spark). A guide to retrieving them from the aircraft can be found on @BudWalker's DatCon website. They are much larger files than the mobile device files, and generally too large to post directly to this forum. The best solution is to upload them to Dropbox or similar and then post a link.
The blue quotes comes from this guide --> Flight log retrieval and analysis guide
