ASP.NET MVC - How to post data to controller using model class

I'm new to ASP.NET MVC development, so I have PortalUsersViewModel:

public class PortalUsersViewModel
{
    public UserInformation User { get; set; }
    public Notification Notification { get; set; }
    public PageDetails PageDetails { get; set; }
    public NewUser NewUser { get; set; }
}

public class NewUser
{
    public UserInformation Information { get; set; }
}

public class UserInformation
{
    public string UserId { get; set; }
    public string Password { get; set; }
    public int Status { get; set; }
    public int Role { get; set; }
    public string FirstName { get; set; }
    public string MiddleName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }
    public string RoleDescription { get; set; }
    public string Gender { get; set; }

    // For change password
    public string CPassword { get; set; }
    public string OldPassword { get; set; }
    public int PwType { get; set; }
}

and my HTML:

@using (Html.BeginForm("CreateUser", "Users", FormMethod.Post))
{
    @Html.AntiForgeryToken()
    <div class="form-row">
        <div class="col-12 col-sm-6 mt-2 mb-2 form-group custom-form-group">
            <input type="text" class="form-control form-control-sm text-capitalize custom-input" name="FirstName" required value="@Model.User.FirstName">
            <label class="small font-weight-bold custom-form-label">First Name<span class="text-danger">*</span></label>
        </div>
        <div class="col-12 col-sm-6 mt-2 mb-2 form-group custom-form-group">
            <input type="text" class="form-control form-control-sm text-capitalize custom-input" name="MiddleName" value="@Model.User.MiddleName">
            <label class="small font-weight-bold custom-form-label">Middle Name</label>
        </div>
        <div class="col-12 col-sm-6 mt-2 mb-2 form-group custom-form-group">
            <input type="text" class="form-control form-control-sm text-capitalize custom-input" name="LastName" required value="@Model.User.LastName">
            <label class="small font-weight-bold custom-form-label">Last Name<span class="text-danger">*</span></label>
        </div>
        <div class="col-12 col-sm-6 mt-2 mb-2 form-group custom-form-group">
            <input type="text" class="form-control form-control-sm text-capitalize custom-input" name="LastName" required value="@Model.User.LastName">
            <label class="small font-weight-bold custom-form-label">Last Name<span class="text-danger">*</span></label>
        </div>
        <div class="col-12 col-sm-6 mt-2 mb-2 form-group custom-form-group">
            <input type="email" class="form-control form-control-sm custom-input" name="Email" required value="@Model.User.Email">
            <label class="small font-weight-bold custom-form-label">Email<span class="text-danger">*</span></label>
        </div>
        <div class="col-12 col-sm-6 mt-2 mb-2 form-group custom-form-group">
            <select name="Gender" class="custom-select custom-select-sm custom-select-1" required>
                <option value="" disabled>Please select your gender</option>
                <option value="M" @(Model.User.Gender == "Male" ? "selected" : "") )>Male</option>
                <option value="F" @(Model.User.Gender == "Female" ? "selected" : "")>Female</option>
            </select>
            <label class="small font-weight-bold custom-form-label">Gender<span class="text-danger">*</span></label>
        </div>
    </div>
    <div class="form-row">
        <div class="col-12 col-sm-3 text-center mt-2 mb-2 form-group mx-auto">
            <button class="btn btn-sm btn-block custom-btn-dark" type="submit"><i class="fas fa-fw fa-plus-circle"></i> Create</button>
        </div>
    </div>
}

and my controller is expecting to receive the posted data like this:

public ActionResult CreateUser(NewUser _user) {
    return Json(_user.Information);
}

I want to get data inside the NewUser object which have the UserInformation object inside. But whenever I submit as post, and print as JSON I don't receive any. Is there something I need to do in my HTML to submit data inside NewUser -> UserInformation?

Seeking your advice. Thanks so much in advance.