No service for type 'Microsoft.AspNetCore.Identity.UserManager`1[Microsoft.AspNetCore.Identity.IdentityUser]' has been registered. code example

Example: InvalidOperationException: No service for type 'Microsoft.AspNetCore.Identity.UserManager`1[Microsoft.AspNetCore.Identity.IdentityUser]' has been registered.

services.AddIdentity<ApplicationUser, IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddDefaultTokenProviders()
    .AddDefaultUI();

services.AddIdentityCore<StudentUser>()
    .AddRoles<IdentityRole>()
    .AddClaimsPrincipalFactory<UserClaimsPrincipalFactory<StudentUser, IdentityRole>>()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddDefaultTokenProviders()
    .AddDefaultUI();

services.AddIdentityCore<EmployeeUser>()
    .AddRoles<IdentityRole>()
    .AddClaimsPrincipalFactory<UserClaimsPrincipalFactory<EmployeeUser, IdentityRole>>()
    .AddEntityFrameworkStores<ApplicationDbContext>()
    .AddDefaultTokenProviders()
    .AddDefaultUI();