I would like to find a way to know programmatically if the device that currently running my app is connected to a "hotspot" network.
I know we can know that it is connected to Wi-Fi by the use of the NWPathMonitor(), which As far as I know it only gives us the info that user is connected to Wi-Fi which could be hotspot, or it could be a public/Enterprise Wi-Fi facility.
The best way to do this is usually to respect the user's preference around Low Data Mode, which is set automatically on some "hotspot" networks. This allows you to better respond to the user's desires, especially if they know more about the network they're on than the system, even if it's not automatically detected as a "hotspot".
Generally, prefer making connections and requests directly while expressing your preferences around expensive and constrained networks and only use a Path Monitor if you have no way to avoid such a pre-flight check.
See this session for more details and additional resources.