Hi Ishani Perera,
Thank you for reaching out to us on Microsoft Q&A forum.
Every month, Microsoft updates preview features in both Power BI Desktop and Power BI Service.
If you're seeing "Data" instead of "Fields," it might be due to a version difference or a setting in your Power BI interface. Ensuring you have the latest updates installed can help align the interface with standard terminology and functionality expected in Power BI.
If you are still facing any issue, please let us know in the comments. We are glad to help you.
If the information is helpful, please Accept Answer so that it would be helpful to community members.
Thank you.