I am getting error 404 in laravel website

I have read other post regarding 404, but solution is not available for my case

I am registering a user for newsletter in website so in web.php

// FrontEnd 
Route::post('store/newsletter','FrontController@StoreNewsletter')->name('store.newsletter');

in index.blade.php in below

<form action=" " method="post" class="newsletter_form">
    @csrf
     <input type="email" class="newsletter_input" required="required"
       placeholder="Enter your email address" name="email">
     <button class="newsletter_button" type="submit">Subscribe</button>
</form>

I even tried changing button to input in form

this is FrontController.php which is in app/Http/Controller/

<?php
namespace App\Http\Controllers;
use Illuminate\Http\Request;
use DB;

class FrontController extends Controller
{
public function __construct(){
    echo 'in frontend controller ';
}


public function StoreNewsletter(Request $request){
    echo 'in frontend controller method';
    $validateData = $request->validate([
        'email' => 'required|unique:newsletters|max:55',
    ]);

    $data = array();
    $data['email'] = $request->email ;
    DB::table('newsletters')->insert($data);

    $notification = array(
        'messege' =>  'Thanks For Subscribing',
        'alert-type' => 'success'
    );
    return Redirect()->back()->with($notification);
}

}

This __construct i have put after error for debug purposes

This is my table name

Schema::create('newsletters', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('email');
        $table->timestamps();
    });