We do not offer Norwegian (Oslo) Equities (Exchange = OSE) via the API. Please note IBKR does offer another Nordic Exchange the NASDAQ OMX Nordic (OMXNO).
If the instrument you wish to monitor data for also trades on NASDAQ OMX then by subscribing to "Nordic (NASDAQ OMX) Equities" you can specify Exchange = OMXNO to query data via the API.
For a listing of historical data available, click here.