@Sathya Sai Cheetirala Welcome to Microsoft Q&A thanks for posting your question.
If it is urgent, then you can check Synapse Link is GA and you can build PBI dashboards using Synapse SQL Serverless.
If you can wait, Fabric Mirroring is in Preview, GA date not defined yet, and you can build PBI dashboards using direct import or SQL Analytics endpoints.
Both SQL engine options have OPENJSON and CROSS APPLY functions, that can help to query JSON nested data.
Regards
Geetha