why url change after click submit button and how to solve that issue ?

I work on asp.net MVC razor page . I face issue Url change from

Resignation/RequesterIndex?filenumber=103085

to

Resignation/Create

after click submit button

so I need URL still as it is before without change after click submit button .

I need after click submit button URL not change so How to do that please ?

What is issue on my code that make this issue .

my code details as below

model ResignationRequester

public class ResignationRequester
{
    [Required]
    [Display(Name = "Dept./ Branch: ")]
    public string Dept { get; set; }

    [Required]
    [Display(Name = "Designation: ")]
    public string Designation { get; set; }

    [Required]
    [Display(Name = "Resignation Submission Date: ")]
    [DataType(DataType.Date, ErrorMessage = "Date only")]
    [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
    public DateTime ResignationSubmissionDate { get; set; }

    [Required]
    [Display(Name = "Mobile No: ")]
    public string MobileNo { get; set; }

@model HR.WorkforceRequisition.Models.ResignationRequester
@{
    ViewBag.Title = "Requester Index";
}
@using (Html.BeginForm("Create", "Resignation", FormMethod.Post, new { enctype = "multipart/form-data", @id = "ResignationForm", style = "padding-top: 50px" }))
{
    @Html.AntiForgeryToken()
<div class="form-horizontal">
    @if (!string.IsNullOrEmpty(ViewBag.errorMsg))
    {
        <div class="alert alert-danger">
            @ViewBag.errorMsg
        </div>
    }
    @if (!string.IsNullOrEmpty(ViewBag.successMessage))
    {
        <div class="alert alert-success">
            @ViewBag.successMessage
        </div>
    }
    <div class="row">
        <div class="form-group col-md-6 hover">
            <div class="col-md-5">
                @Html.LabelFor(model => model.Dept, htmlAttributes: new { @class = "control-label" })
            </div>

            <div class="col-md-7">
                @Html.EditorFor(model => model.Dept, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Dept, "", new { @class = "text-danger" })
            </div>
        </div>
        <div class="form-group col-md-6 hover">
            <div class="col-md-5">
                @Html.LabelFor(model => model.Designation, htmlAttributes: new { @class = "control-label" })
            </div>

            <div class="col-md-7">
                @Html.EditorFor(model => model.Designation, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Designation, "", new { @class = "text-danger" })
            </div>
        </div>
    </div>
    <div class="row">
        <div class="form-group col-md-6 hover">
            <div class="col-md-5">
                @Html.LabelFor(model => model.ResignationSubmissionDate, htmlAttributes: new { @class = "control-label" })
            </div>

            <div class="col-md-7">
                @Html.EditorFor(model => model.ResignationSubmissionDate, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.ResignationSubmissionDate, "", new { @class = "text-danger" })
            </div>
        </div>
        <div class="form-group col-md-6 hover">
            <div class="col-md-5">
                @Html.LabelFor(model => model.MobileNo, htmlAttributes: new { @class = "control-label" })
                <span class="text-danger"> *</span>
            </div>

            <div class="col-md-7">
                @Html.EditorFor(model => model.MobileNo, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.MobileNo, "", new { @class = "text-danger" })
            </div>
        </div>
    </div>
    <div class="form-group">
        <div class="col-md-offset-0 col-md-12">
            <input type="submit" value="Submit" class="btn btn-success" />
        </div>
    </div>
</div>
}
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Create(ResignationRequester resignationRequester)
        {
                if (ModelState.IsValid)
                {
                    try
                    {
                        Workforce.InsertToReignation(resignationRequester);
                    }
                    catch (Exception ex)
                    {
                        ViewBag.errorMsg = "Create Not Done Correctly";
                    }
                    Session[SessionKeys.DirectManager] = GetEmployeeName(Convert.ToString(resignationRequester.DirectManager));
                    Session[SessionKeys.LineManager] = GetEmployeeName(Convert.ToString(resignationRequester.LineManager));
                    if (string.IsNullOrEmpty(ViewBag.errorMsg))
                    {
                        ViewBag.successMessage = "Resignation Submission form Created successfully";
                    }
                }
                else
                {
                    var errors = ModelState.Select(x => x.Value.Errors)
                                            .Where(y => y.Count > 0)
                                            .ToList();
                    ViewBag.errorMsg = "Some Required Fields Not Added";
                }
            }
           
           return View(resignationRequester);
  
        }