That's great!
I heard a preacher on the radio once tell of his daughter's friends TPing their house. So he took his daughter to COSTCO and bought the BIG package of TP...
As this is a DJI drone, take this to the forum forum.dji.com. Also, submit a support ticket. The DJI people will help figure out what went wrong and if it was a defect in the drone, will provide another. DJI support is pretty good.
Your OTG isn't working?
Um... On an iPhone, the phone always reports "unsupported device" because it doesn't know how to back up to or show pictures or play videos from a spark remote. Just click that away as GO 4 knows what it is.