The Mavic requires DJI Assistant 2.x to flash the firmware and calibrate sensors, etc. Available downloads from DJI
PC: https://dl.djicdn.com/downloads/dji_assistant/20200113/DJI+Assistant+2+For+Mavic+2.0.10.exe
Mac: https://dl.djicdn.com/downloads/dji_assistant/20191030/DJI+Assistant+2+For+Mavic+2.0.10.pkg
You can use Assistant 1.1.2 to enable debug mode and see some parameters, but not many.