I had a mini briefly before I returned it to upgrade to the M2. I found a factory reset option somewhere in the DJI app settings. I no longer have the same app so can't tell you exactly how to find it. But it is there somewhere. Don't forget to remove your sd card.
Thanks for replying. Yes I remove the sd and already pass it to the new owner. Didn't reset anything but that must be flying parameters and no sensitive info. Thanks again