ek.get_timeserires | 404 error : Error code 404

trying to get the python example working. i got a Dev API key, but when i run the time series api call: ek.get_timeseries([MSFT.O], start_date=2016-01-01, end_date=2018-07-26) i get a 404 error : Error code 404 | Client Error: Cannot POST /api/v1/data.

python code:

import eikon as ek

ek.set_app_key('***************')

ek.get_timeseries(["MSFT.O"], start_date="2016-01-01", end_date="2018-07-26")

I am able to use Eikon app to get price history

I generated the key using Eikon