For realtime data, it does not support ISIN instrument.
I only support RIC.
So you need to convert ISIN to RIC first.
This is example TR function.
Eikon Excel is a desktop product (part of Eikon).
If you need further help, you can contact Refinitiv Helpdesk in your country.
This forum is for Eikon Data API (in Python language) example/usage question.