Microsoft Fabric is not replacing Power BI and Power Bi service is still available at: https://app.powerbi.com/
Microsoft Fabric is a SaaS platform that includes a number of technologies that include Data Factory, Azure Synapse Analytics, Azure Data Warehouse, Data Science, and Power BI.
Power Bi is Microsoft’s primary application for creating reports and dashboards along side paginated reports. So Power BI isn’t going away and will not be replaced, it will merely be part of the MS Fabric platform.