Sources:

ISAPI defines a set of standard HTTP requests that allow third-party software to control the panel. Want to integrate the DS-K2604T into a building management system (BMS) that triggers lights when someone badges in? Or perhaps link it to a time-and-attendance payroll system? The firmware exposes these endpoints via ISAPI.

Click Upgrade and wait for the system to complete the script and restart. Troubleshooting Common Upgrade Failures Potential Cause Actionable Solution "Language Mismatch" Error

Click on the Upgrade button at the top or side menu.