Ajax alert message persists after clicking okay button

my code works alright but the alert message in the browser doesn’t go away after I click the okay button inside the alert success prompt. I’ve tried all I can but still persists. Please help.

HTML

<button  id="flag-post" data-post-id="{{ $counter->id }}">Report this</button>

Route

Route::get('/flag', [AppHttpControllersApplicationsController::class, 'flagPost'])->name('flag.post');

Controller

 public function flagPost(Request $request)
{
   
    $postId = $request->input('post_id');
    
    $post = Job::findOrFail($postId);
    
    $post->increment('flags');
    
    return response()->json(['success' => true]);
}

Javascript

<script>
    $(function() {
    $('#flag-post').click(function() {
    // Retrieve the post ID from the button's data attribute
    var postId = $(this).data('post-id');
    
    // Send an AJAX request to the flag post route
    $.ajax({
        url: "{{ route('flag.post') }}",
        type: "GET",
        data: {
            post_id: postId,
            _token: "{{ csrf_token() }}"
        },
        success: function(response) {
            // Alert the user that the post has been flagged
            alert("Thank you for flagging this post!");
        },
        error: function(xhr, status, error) {
            // Alert the user that there was an error
            alert("Error: " + error);
        }
    });
});
});

    </script>