Before updating the firmware - make sure that the terminal is charged to at least 51%. Preferably - leave the terminal charging during the whole updating process.
Enter <App&Firmware> and check the <Installed Firmware>, it will show the currently installed firmware, e.g. PayDroid_7.1.2_Aquarius_V02.5.36_20240229
PayDroid_7.1.2 - the number here corresponds to Android version (8.1),
V02.5.36 - this is the version number,
20240229 - this is the date when the firmware was updated last time.
Make sure that the terminal has the most recent firmware installed that corresponds to the Android version currently installed on the terminal and that the version number is the latest.
Access <Push Task>, press section <Firmware>, and press <+ Firmware>.
A pop up <Add Push Firmware> will be displayed with a list of available firmware. Look only for the firmware that corresponds to the Android version.
Check whether there are any newer firmware versions rather than that currently installed on the terminal. Look only at version number, do not look at <Updated Time> since some older versions may be re-uploaded at later date and appear as the last updated.
If there is a newer version (currently there are 2025 firmware versions), select it and press <Ok>.
A new section with firmware installation details will open, press <Activate>.
Do not perform any other activities with the terminal when the firmware is being upgraded.
The terminal will display a status screen and the process may last 10-15 minutes depending on the connectivity. An automatic restart will happen during the firmware upgrade. A successful installation will display a notification of the completed upgrade and in section <Push Task> <Operation History> the firmware will appear as installed.