Streaming Z spread

Hello everyone,
I'm new to refinitiv and I would like to start streaming data. I managed to get BID_YIELD data however I could not manage to do the same for ZSPREAD.

Thanks in advance for your help

Here is the code

import refinitiv.data as rd
from refinitiv.data.content import pricing
rd.open_session ()

streaming = rd.content.pricing.Definition (
     ['DE2YT=RR', 'DE10YT=RR'],
     fields = ['BID_YIELD', 'ZSPREAD', 'ZSpreadBp', 'TR.ZSpreadAnalytics']
).get_stream ()

streaming.open (with_updates = True)
streaming.get_snapshot()