Connect the head unit to a reliable (e.g., your phone's hotspot). Navigate to Settings > System > System Upgrade . Select Online Upgrade to check for new versions.

: If an update is found, download it. The unit will prompt you to restart once finished. 2. Manual USB Update

Say "Proceed" to continue with that assumed content, or reply with one of:

Updating usually requires a formatted USB drive and specific firmware files. Android Head Unit firmware update

If your current Android YT9216BJ00012V001 unit is working fine—do not update. There is a saying in car audio: "If it ain't broke, don't flash it."