@Carlos Rodriguez - Thanks for the question and using MS Q&A platform.
It seems like you are having trouble getting schema data for your Fabric tenant datasets in Azure Purview. Have you checked if the schema data is available in the Fabric Semantic Model (FSM) metadata? If the schema data is not available in the FSM metadata, then it won't be available in the scan results.
Supported capabilities: Scanning a Microsoft Fabric tenant will automatically bring in metadata and lineage from Fabric items including Power BI into Microsoft Purview Data Catalog.
Known limitations: Currently for all Fabric items besides Power BI, only item level metadata and lineage will be scanned. Scanning metadata and lineage of sub level items like Lakehouse tables or files isn't yet supported.
For more details, refer to How to get lineage from Microsoft Fabric items into Microsoft Purview.
I hope this helps! Let me know if you have any other questions.