Injecting IHubContext into my background service for SignalR in .NET 5

i have a hub class

       public class MyHub : Hub {
    private readonly AppDbContext _dbContext;
       
    public MyHub(AppDbContext dbContext)
    {
        _dbContext = dbContext;
    }

    public override Task OnConnectedAsync()
    {
        // Implementation
    }
}

when i try to inject Ihubcontext and run the app i get: unable to resolve service for type Microsoft.AspNet.SignalR.IHubContex

public class NotificationService : BackgroundService
{
private readonly IHubContext<MyHub> _hubContext;
private readonly AppDbContext _dbContext;
private int lastProcessedNotificationId = 0;
public NotificationService(IHubContext<MyHub> hubContext, AppDbContext dbContext)
{
_dbContext = dbContext;
_hubContext=hubContext;

        }
        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            while (!stoppingToken.IsCancellationRequested)
            {
              
                await _hubContext.Clients.All.SendMessageToAll("Test");
    
            }
        }
    }

i expect to be injected like in my controller it works

You are using wrong package. In your project, you should use Microsoft.AspNetCore.SignalR package, instead of Microsoft.AspNet.SignalR.

You need to uninstall the Microsoft.AspNet.SignalR package, since signalr is build-in feature in asp.net core. You don't need to add any packages. You can use it like below in the .cs file namespace.

using Microsoft.AspNetCore.SignalR;

And for J.Memisevic's comment, we want to check how you register the background service.

Something like

builder.Services.AddHostedService<NotificationService>();