designtopack/public/site/plugins/notifications/routes/read.php

<?php

return [
  'pattern' => '(:all)read-notification.json',
  'method' => 'POST',
  'action'  => function () {
      $json = file_get_contents('php://input');
      $data = json_decode($json);

      try {
        $project = page("projects")->findPageOrDraft($data->projectId);
        
        $project->readNotification($data->notificationId);
        return json_encode([
          "status" => "success"
        ]);
      } catch (\Throwable $th) {
        return json_encode([
          "status" => "error",
          "message" => $th->getMessage() . ' line ' . $th->getLine() . " in file " . $th->getFile()
        ]);
      }
  }
];