code: public function onKernelResponse(FilterResponseEvent $event): void
      {
          if (!$this->scopeMatcher->isContaoMasterRequest($event)) {
              return;
          }
  
          $token = $this->tokenStorage->getToken();
  
          if (null === $token || $this->authenticationTrustResolver->isAnonymous($token)) {
              return;
          }
  
          $user = $token->getUser();
  
          if (!$user instanceof User) {
              return;
          }
  
          /** @var AttributeBagInterface $sessionBag */
          $sessionBag = $this->getSessionBag($event->getRequest());
          $data = $sessionBag->all();
  
          $this->connection->update($user->getTable(), ['session' => serialize($data)], ['id' => $user->id]);
      }
docs: Writes the current session data to the database.