// in Startup.cs, ConfigureServices()
   services.AddTransient<HubConnectionBuilder>();

// in Component class
[Inject]
private HubConnectionBuilder _hubConnectionBuilder { get; set; }

// in Component Initialization code
var connection = _hubConnectionBuilder // the injected one from above.
        .WithUrl("/myHub", // The hub URL. If the Hub is hosted on the server where the blazor is hosted, you can just use the relative path.
        opt =>
        {
            opt.LogLevel = SignalRLogLevel.Trace; // Client log level
            opt.Transport = HttpTransportType.WebSockets; // Which transport you want to use for this connection
        })
        .Build(); // Build the HubConnection

connection.On("Receive", this.Handle); // Subscribe to messages sent from the Hub to the "Receive" method by passing a handle (Func<object, Task>) to process messages.
await connection.StartAsync(); // Start the connection.

await connection.InvokeAsync("ServerMethod", param1, param2, paramX); // Invoke a method on the server called "ServerMethod" and pass parameters to it. 

var result = await connection.InvokeAsync<MyResult>("ServerMethod", param1, param2, paramX); // Invoke a method on the server called "ServerMethod", pass parameters to it and get the result back.