Cannot send message to group in SignalR

Question

So I have the below code, which I am trying to make it send the message when I join the group, but it is not working

   public async Task JoinGroup()
        {
            await Groups.AddToGroupAsync(Context.ConnectionId, "Hello");
            await Clients.Group("Hello").SendAsync("SEND", $"{Context.ConnectionId} has been added");
        }

When I try it like this

  public async Task JoinGroup()
        {
            await Groups.AddToGroupAsync(Context.ConnectionId, "Hello"); 
            await Clients.All.SendAsync("SEND", $"{Context.ConnectionId} has been added");
        }

It works, but it sends the message to all the connected clients, which I do not want to happen.

I got the first code block from the docs. https://docs.microsoft.com/en-us/aspnet/core/signalr/groups?view=aspnetcore-6.0

Anyone have any idea why it is not working?

Edit: I have a listener in the front

 connection.on("SEND", message => alert(message))

Answer 1

For sending message in group, should use .Group instead .All.

    await Clients.Group.SendAsync("SEND", $"{Context.ConnectionId} has been added");