Расширение для MongoDB.Driver

Install-Package Apteryx.MongoDB.Driver.Extend

public class Account : BaseMongoEntity
{
    public string Name { get; set; }
    public string Mobile { get; set; }
}

public class MyDbService : MongoDbService
{
    public MyDbService(IOptionsMonitor<MongoDBOptions> options) : base(options) {}
    public IMongoCollection<Account> Account => _database.GetCollection<Account>("Account");
}

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddMongoDB<MyDbService>(options =>
        {
            options.ConnectionString = Configuration.GetConnectionString("MongoDbConnection");
        });
        //.....................
    }
}

[Route("api/[controller]")]
[ApiController]
public class ValuesController : ControllerBase
{
    private readonly MyDbService db;

    public ValuesController(IMongoDbService db)
    {
        this.db = (MyDbService)db;
    }

    // GET api/values
    [HttpGet]
    public ActionResult<IEnumerable<string>> Get()
    {
        db.Account.InsertOne(new Account() { Name = "Иванов", Mobile = "+79123456789" });
        return new string[] { "значение1", "значение2" };
    }
}

public class Account : BaseMongoEntity
{
    public string Name { get; set; }
    public string Mobile { get; set; }
}

public class MyDbService : MongoDbService
{
    public MyDbService(string conn) : base(conn) {}

    public IMongoCollection<Account> Account => _database.GetCollection<Account>("Account");
}

[Route("api/[controller]")]
[ApiController]
public class ValuesController : ControllerBase
{
    // GET api/values
    [HttpGet]
    public ActionResult<IEnumerable<string>> Get()
    {
        var db = new MyDbService("mongodb://user:pwd@xxx.xxx.xxx.xxx:27017/testdb?authSource=admin");
        db.Account.InsertOne(new Account() { Name = "Петров", Mobile = "+79123456780" });
        return new string[] { "значение1", "значение2" };
    }
}