Hi mehad,
Refer the below html. LinkButton doesnot have property NavigateUrl, it has PostBackUrl.
<div>
<asp:LinkButton ID="lbNavigate" Text="Details" runat="server" OnClick="lbNavigate_Click" />
</div>
Code
protected void lbNavigate_Click(object sender, EventArgs e)
{
string userType = "admin"; //Get usertype as per your logic.
if (userType.ToLower() == "admin")
{
lbNavigate.PostBackUrl = "~/app/admin/Default.aspx";
}
else
{
lbNavigate.PostBackUrl = "~/app/Default.aspx";
}
}