Firmware Upgrade mode, and then run the Firmware Loader application to install the updated firmware on the radio.

With the external power source OFF, hold down both the P1 button AND the round, orange button to the left of P1 at the same time. With both buttons held down, turn the external power source ON. When the display starts flashing, you can release the buttons. This indicates you are in Firmware Upgrade mode.

TYT MD-9600 Upgrading the Programming Software Guide

*** Firmware Upgrade mode, and then run the Firmware Loader application to install the updated firmware on the radio.

TYT MD-9600 Firmware Upgrade mode
With the external power source OFF, hold down both the P1 button AND the round, orange button to the left of P1 at the same time. With both buttons held down, turn the external power source ON. When the display starts flashing, you can release the buttons. This indicates you are in Firmware Upgrade mode.