From what you’re describing, it sounds like the core issue is actually the role separation between the two applications rather than just a wrong value in the connection dialog.
In that setup, Inventoria acts as the server-side application because it holds the inventory database and exposes the data through its web access service. So in the Express Accounts integration screen, the “server program” is essentially your Inventoria instance running on the machine where the data lives.
A few clarifications that usually trip people up:
Access Authorization Code → this is not your registration code, but the API/web access authorization token generated inside Inventoria’s web access settings.
IP / Address → yes, this should be the machine running Inventoria (often local network IP rather than the public/web URL).
Port → must match the web access port configured in Inventoria exactly.
Location name → just a label for the business profile; it doesn’t affect connectivity.
The “Conn.” result usually means it sees the endpoint but fails during authentication handshake, which often points to either:
wrong authorization code format, or
firewall blocking the port, or
Inventoria web access not fully enabled for external connections (only localhost).
On your second question: if your goal is inventory + AR + reporting (sales, item breakdown, overdue accounts), Express Invoice can often cover most of that without needing Express Accounts, depending on how deep your accounting requirements go. Express Accounts becomes more relevant when you need full double-entry accounting rather than just operational reporting.