It is supposed to use a keyboard (numeric keypad) connected via OTG. The keys on the screen also work, but they are more for navigating on a real keyboard.
At the end of the input, a packet with the entered data is sent to the server (with the server part of this program installed). Program parameters can be loaded into it, they are stored as a text file of a certain format.
The server part and the file format are a different story. This is a development for a specific client.