A working example for Integrating DotnetCore, EfCore, CosmosDb provider for EFCore 3.0, Cosmos Db Emulator
- Dotnet Core SDK 3.0 - here
- Cosmos Db Emulator - here
- Cosmos Db Provider for EF Core - nuget package
dotnet add package Microsoft.EntityFrameworkCore.Cosmos
https://docs.microsoft.com/en-us/ef/core/providers/cosmos/?tabs=dotnet-core-cli