Follow the following tutorial: https://docs.microsoft.com/en-us/powerapps/developer/common-data-service/walkthrough-blazor-webassembly-single-tenant
Make your App Registration to authenticate with Accounts in any organizational directory (Any Azure AD directory - Multitenant)
This Blazor WebAssembly application uses Global Discovery Service (GDS) to get CDS Instances and populates an Environments dropdown. It shows how to fetch Accounts
Try it out here: https://blazorcds.mohsinonxrm.com