ASP.NET webforms VB using username instead of email as username - asp.net

Question

I don't want use email as username, I amended the code to add first name and last name but cant get it to use usernames, it keeps going to email in aspnetusers table
I'd like the users to navigate to other users using their username and keeping emails confidential
Protected Sub Unnamed4_Click(sender As Object, e As EventArgs)
If Me.Password.Text = Me.ConfirmPassword.Text Then
Dim userName As String = signinSrEmail.Text
Dim manager = Context.GetOwinContext().GetUserManager(Of ApplicationUserManager)()
Dim signInManager = Context.GetOwinContext().Get(Of ApplicationSignInManager)()
Dim user = New ApplicationUser() With {.UserName = userName, .Email = userName, .FirstName = TextBoxFname.Text, .Surname = TextBoxSName.Text}
Dim result = manager.Create(user, Password.Text.ToString)
If result.Succeeded Then
'For more information on how To enable account confirmation And password reset please visit https://go.microsoft.com/fwlink/?LinkID=320771
Dim code = manager.GenerateEmailConfirmationToken(user.Id)
Dim callbackUrl = IdentityHelper.GetUserConfirmationRedirectUrl(code, user.Id, Request)
manager.SendEmail(user.Id, "Confirm your account", "Please confirm your account by clicking here.")
If user.EmailConfirmed Then
'Response.Cookies("UserName").Expires = DateTime.Now.AddDays(30)
FormsAuthentication.SetAuthCookie(user.Id, False)
signInManager.SignIn(user, isPersistent:=False, rememberBrowser:=True)
IdentityHelper.RedirectToReturnUrl(Request.QueryString("ReturnUrl"), Response)
Else
ErrorMessage.Text = "An email has been sent to your account. Please view the email and confirm your account to complete the registration process."
End If
Else
errormessage.Text = result.Errors.FirstOrDefault()
End If
Else
errormessage.Text = "Passwords do not match"
End If
End Sub
End Class

Answer 1

You are storing Email Id in userName. if you don't want to use email as user name then you have to use this
Dim userName As String = TextBoxFname.Text +" "+.Surname = TextBoxSName.Text