How to connect to second database in WebhookController.php of the laravel cashier?

How to connect to second database in WebhookController.php of the laravel cashier? I want to update some data in the second database when triggered to WebhookController in laravel. But failed. It returns 500 internal error. Please help me. Thank you.

protected function handleCustomerSubscriptionUpdated(array $payload)
{
    $username = 'xxx';

    if ($user = $this->getUserByStripeId($payload['data']['object']['customer'])) {
        $data = $payload['data']['object'];

        $user->subscriptions->filter(function ($subscription) use ($data) {
            return $subscription->stripe_id === $data['id'];
        })->each(function ($subscription) use ($data, $user) {
            /*
            if (
                isset($data['status']) &&
                $data['status'] === StripeSubscription::STATUS_INCOMPLETE_EXPIRED
            ) {
                $subscription->items()->delete();
                $subscription->delete();

                return;
            }

            $firstItem = $data['items']['data'][0];
            $isSinglePrice = count($data['items']['data']) === 1;

            // Price...
            $subscription->stripe_price = $isSinglePrice ? $firstItem['price']['id'] : null;

            // Quantity...
            $subscription->quantity = $isSinglePrice && isset($firstItem['quantity']) ? $firstItem['quantity'] : null;
            */

            // Trial ending date...
            if (isset($data['trial_end'])) {
                $trialEnd = Carbon::createFromTimestamp($data['trial_end']);

                if (! $subscription->trial_ends_at || $subscription->trial_ends_at->ne($trialEnd)) {
                    $subscription->trial_ends_at = $trialEnd;
                }
            }

            // Cancellation date...
            if (isset($data['cancel_at_period_end'])) {
                if ($data['cancel_at_period_end']) {
                    $subscription->ends_at = $subscription->onTrial()
                        ? $subscription->trial_ends_at
                        : Carbon::createFromTimestamp($data['current_period_end']);
                } elseif (isset($data['cancel_at'])) {
                    $subscription->ends_at = Carbon::createFromTimestamp($data['cancel_at']);
                } else {
                    $subscription->ends_at = null;
                }
            }

            // Status...
            if (isset($data['status'])) {
                $subscription->stripe_status = $data['status'];
                
                if ($data['status'] != 'active') {
                    $customer_id = $data['customer'];
                    $res = DB::connection('mysql')->table('users')->where('stripe_id', $customer_id)->limit(1)->get();
                    if ( $res->count() == 1 ) {
                        $x_res = DB::connection('mysql2')->table('users')->where('email', $res->email)->limit(1)->get();
                        if ( $x_res->count() == 1 ) {
                            DB::connection('mysql2')->table('users')
                                ->where('email', $res->email)
                                ->update([
                                    'admin_enabled' => 0,
                                    'enabled' => 0
                                ]);
                        }
                    }

                    $user->forceFill([
                        'status' => 'inactive'
                    ])->save();
                } else {
                    $user->forceFill([
                        'status' => 'active'
                    ])->save();

                    // $customer_id = $data['customer'];
                    // $res = DB::connection('mysql')->table('users')->where('stripe_id', $customer_id)->limit(1)->get();
                    // if ( $res->count() == 1 ) {
                    //     $x_res = DB::connection('mysql2')->table('users')->where('email', $res->email)->limit(1)->get();
                    //     if ( $x_res->count() == 1 ) {
                    //         DB::connection('mysql2')->table('users')
                    //             ->where('email', $res->email)
                    //             ->update([
                    //                 'admin_enabled' => 1,
                    //                 'enabled' => 1
                    //             ]);
                    //     }
                    // }
                }
            }

            $subscription->save();

            /*
            // Update subscription items...
            if (isset($data['items'])) {
                $prices = [];

                foreach ($data['items']['data'] as $item) {
                    $prices[] = $item['price']['id'];

                    $subscription->items()->updateOrCreate([
                        'stripe_id' => $item['id'],
                    ], [
                        'stripe_product' => $item['price']['product'],
                        'stripe_price' => $item['price']['id'],
                        'quantity' => $item['quantity'] ?? null,
                    ]);
                }

                // Delete items that aren't attached to the subscription anymore...
                $subscription->items()->whereNotIn('stripe_price', $prices)->delete();
            }
            */
        });
    }

    return new Response($username, 200);
}