Adding a CSV file ASP.NET - asp.net

Question

Currently on a project to create a check-in system and I'm creating this in ASP.NET MVC. I'm at the stage where I'm in my ImportController and using the Nuget package CsvHelper.
I'm getting errors including 'No overload for method 'Add' takes 3 arguments. Is anyone able to help? I've included a snip of my code below.
Any help would be much appreciated :)
[Route("import")]
public class ImportController : Controller
{
private readonly AppDbContext _appDbContext;
public ImportController(AppDbContext appDbContext)
{
_appDbContext = appDbContext;
}
[HttpGet("")]
public IActionResult Index()
{
return View();
}
public IActionResult Index(ImportIndexViewModel vm)
{
if (ModelState.IsValid)
{
using (var csvStream = new StreamReader(vm.File.OpenReadStream()))
using (var csv = new CsvReader(csvStream))
{
csv.Read();
csv.ReadHeader();
while (csv.Read())
{
try
{
// Application reference
var AdmissionNumber = csv["Admission Number"];
var Firstname = csv["Students Firstname"];
var Surname = csv["Students Surname"];
if (string.IsNullOrWhiteSpace(AdmissionNumber))
throw new NullReferenceException("admissionNumber");
if (string.IsNullOrWhiteSpace(Firstname))
throw new NullReferenceException("Forename");
if (string.IsNullOrWhiteSpace(Surname))
throw new NullReferenceException("Surname");
// Add student to system
_appDbContext.Students.Add(AdmissionNumber.Trim(), Firstname.Trim(), Surname.Trim());
}
catch (NullReferenceException ex)
{
throw;
Console.WriteLine($"'{ex.Message}' is missing from row {csv.Context.Row}");
}
}
}
}
return View(vm);
}
}
}
Here is the exception stack it's providing me when I click upload. I think this again is due to this line here: _appDbContext.Students.Add(AdmissionNumber.Trim(), Firstname.Trim(), Surname.Trim());
System.InvalidOperationException: Could not create an instance of type 'System.Func`1[[SelfRegister.WebApp.Models.StudentsIndexViewModel+StudentViewModel, SelfRegister.WebApp, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]'. Model bound complex types must not be abstract or value types and must have a parameterless constructor. Alternatively, give the '_appDbContext' parameter a non-null default value.
at Microsoft.AspNetCore.Mvc.ModelBinding.Binders.ComplexTypeModelBinder.CreateModel(ModelBindingContext bindingContext)
at Microsoft.AspNetCore.Mvc.ModelBinding.Binders.ComplexTypeModelBinder.BindModelCoreAsync(ModelBindingContext bindingContext, Int32 propertyData)
at Microsoft.AspNetCore.Mvc.ModelBinding.ParameterBinder.BindModelAsync(ActionContext actionContext, IModelBinder modelBinder, IValueProvider valueProvider, ParameterDescriptor parameter, ModelMetadata metadata, Object value)
at Microsoft.AspNetCore.Mvc.Controllers.ControllerBinderDelegateProvider.<>c__DisplayClass0_0.<<CreateBinderDelegate>g__Bind|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
--- End of stack trace from previous location where exception was thrown ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)
at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)