{'success': False, 'message': 'Invalid Token', 'errorCode': 'AG8001', 'data': ''}

[yrj.panchal]

I'm getting this error. can you help me on this. I have validated my Token is correct.
API_KEY = 'xxxxxxx'
angel_obj = SmartConnect(api_key=API_KEY)

Queries:

1. do we need to authenticate this 'angel_obje' using generateSession() or directly we can use this for Historical data.
2. angel_obj = SmartConnect(api_key=API_KEY), do we need to use only once in our code or need to use again again as per the uses.