See MultiTenancyServer README.

All examples will register two tenants (tenant1 and tenant2) along with three users with one user, alice, registered within both tenants. You should launch a sample project as an exe when debugging instead of via IIS Express so the /seed command line argument is passed in which will generate the Sqlite database(s) in the project folder and populate with the above mentioned tenants and users. All user passwords are Pass123$.

Sample project: AspNetIdentityAndEFCore
Components: ASP.NET Core Identity and Entity Framework Core
Database model: single database with tenancy shadow columns

Sample project: Int64AspNetIdentityAndEFCore
Components: ASP.NET Core Identity and Entity Framework Core
Database model: single database with tenancy shadow columns

Sample project: IdentityServerWithAspIdAndEF
Components: Identity Server 4, ASP.NET Core Identity and Entity Framework Core
Database model: single database with tenancy shadow columns

Sample project: DatabasePerTenantAspIdAndEF
Components: ASP.NET Core Identity and Entity Framework Core
Database model: database per tenant