STELLINA has a built-in Wi-Fi connection. You do not necessarily need an internet connection to connect to STELLINA. The station is like a residential (home) gateway to which you can connect via a Wi-Fi connection.
The Gravity by Vaonis app will not offer a dedicated mode for this type of observation. However, it will still be possible to observe distant objects by day (landscapes, animals, etc.) using Hestia and your smartphone’s camera.