can't download dgi go 4 on my ipad mini 4

Just got a refurbished IPad 4 16 Gb. When I try to download DJI Go 4.07, I get the message that the "...App is not compatible with your device". The only other option in the AppStore is Go 3, which it Phantom, Matrice, SSMO, and Inspire, but not Mavic. Any suggestions?