To update your AMS-1 terminal from C1ST Pay, the terminal will ask for a code.
The code is 1419.
If the update fails the first time, you should:
Tap the cogwheel to go to Settings
Select Device information
Select Software version
When the terminal asks for the code, enter 1419 and download the update.
Note! You can use the terminal while the update is downloading, but the terminal may restart during the process.