Eikon API - Python.
I'm trying to get the timeseries of a paid index, (.JGEMBLA) but It only gets the last value of the field.
The Eikon Data API presently provides the get_data() and get_timeseries() calls which as far as I'm aware unfortunately does not provide historical data that maps to the RHistory function. See this related post for an explanation and possible suggestions.
Looking within the DIB (Data Item Browser), I don't see any historical data offered for the Beta Value.
To view the available historical values offered for an instrument, you can narrow down the filter within the DIB:
You may also want to confirm with the Refinitiv Helpdesk and ask whether this data is available for this or any other historical data points you may need.