That looks like it doesn't have any local-first functionality? Their API documentation only talks about how to retrieve data from their server, even if you are just trying to get the data from your own station.
Does it? I couldn't find any documentation on those features, if you have links to any documentation that doesn't require going through their servers I'd love to see it since I've been looking for something just like that. Everything I have found, even for querying a single devices, requires making a request to swd.weatherflow.com via an internet connection.