Geovonic connects to your ArcGIS Enterprise via the Geovonic Relay Service. If your ArcGIS is configured to use Integrated Windows Authentication (IWA), you must add the NTLM credentials in to the relay service configuration file.
The NTLM user must have an org_admin role in your ArcGIS portal during setup. It should be switched to lower privilege account after setup is complete.
The NTLM user needs to be able to lookup feature layers on your ArcGIS portal.
Windows Service (Default)
When installing the Geovonic Relay Service as a Windows service, you will download the config.ini file from the Geovonic admin console. The config.ini file includes three lines for NTLM_DOMAIN, NTLM_USERNAME, NTML_PASSWORD. These must be filled in with the appropriate values.
Restart your Windows service after modifying the config.ini file.