Unable to resolve service for type 'Microsoft.AspNetCore.SignalR.IHubContext code example

Example: Unable to resolve service for type 'Microsoft.AspNetCore.Identity.UserManager

services.AddIdentity<Automobile.Models.Account, IdentityRole>(options =>
    {
        options.User.RequireUniqueEmail = false;
    })
    .AddEntityFrameworkStores<Providers.Database.EFProvider.DataContext>()
    .AddDefaultTokenProviders();