How to calculate total sales

I want to get total sales from completed orders. there is no error but I can't get the total sales when order is completed

here is my code

my order table migrate

     public function up()
		{
   		 Schema::create('orders', function (Blueprint $table) {
        		$table->id();
        		$table->integer('customer_id');
        		$table->string('order_date');
        		$table->string('order_status');
        		$table->string('total_products');
        		$table->string('sub_total')->nullable();
        		$table->string('vat')->nullable();
        		$table->string('invoice_no')->nullable();
        		$table->string('total')->nullable();
      		    $table->string('payment_status')->nullable();
        		$table->string('pay')->nullable();
        $table->string('due')->nullable();
        $table->timestamps();
    });
}

in my Controller

			public function TodaySales(){
   				 $date = date("d-m-Y");
                     $today = Order::where('order_date',$date)->get();
                     $orders = Order::where('order_status','complete')->get();
               return view('backend.sales.today_sales',compact('today','orders'));
				} // End Method

Blade file

	 @extends('layout.master')
      @section('content')
     <div class="content">

                <!-- Start Content-->
                <div class="container-fluid">

                    <!-- start page title -->
                    <div class="row">
                        <div class="col-12">
                            <div class="page-title-box">
                                <div class="page-title-right">
                                    <ol class="breadcrumb m-0">
                                        
                                    </ol>
                                </div>
                                <h4 class="page-title">Today Sales</h4>
                            </div>
                        </div>
                    </div>     


                    <!-- end page title --> 
    {{-- calculate total daily sales --}}
     @php
    $date = date("d-m-Y");
    $sales = App\Models\Order::where('order_date',$date)->sum('pay');
     @endphp
  {{-- end --}}



<div class="row">
    <div class="col-12">
        <div class="card">
            <div class="card-body">

       <h4 class="header-title"> Today Sales </h4>   
       <h4 style="color:white; font-size: 30px;" align="center"> Total : ₵{{ $sales }}</h4>     
        
                <table id="basic-datatable" class="table dt-responsive nowrap w-100">
                    <thead>
                        <tr>
                            <th>Sl</th>
                            <th>Order Date</th>
                            <th>Payment Method</th>
                            <th>Invoice Number</th>
                            <th>Amount</th>
                           
                            
                        </tr>
                    </thead>


    <tbody>
    	@foreach($today as $key=> $item)
        <tr>
            <td>{{ $key+1 }}</td>
            <td>{{ $item->order_date }}</td>
            <td>{{ $item->payment_status }}</td>
            <td>{{ $item->invoice_no }}</td>
            <td>{{ $item->pay }}</td>
        </tr>
        @endforeach
    </tbody>
                </table>

            </div> <!-- end card body-->
        </div> <!-- end card -->
    </div><!-- end col-->
</div>
<!-- end row-->




                </div> <!-- container -->

            </div> <!-- content -->


 @endsection