Hi stkm2017,
I was in the process of writing the answer while you posted the solution. For the sake of completeness here is mine:
You can retrieve states for your own device only by providing login credentials. Just pass your username and password as constructor arguments:
api = OpenSkyApi("username", "password")
The library uses Python's built-in logging facilities. You can see what's going on under the hood as follows:
from opensky_api import OpenSkyApi
import logging
import sys
logging.basicConfig(stream=sys.stdout, level=logging.DEBUG)
api = OpenSkyApi() # sic!
s = api.get_my_states(serials=[...])
print(s)
The output looks like this:
DEBUG:opensky_api:Blocking request: Authentication required
None
Hope that helps!
Cheers,
Markus