Thanks, I got and please reference the following.

[2019-11-06 23:00:45] front.ERROR [070oqfhvslbud21fd2m66hunr1] [a6c26eb] [2] [Eccube\Log\Logger:log:66] - システムエラーが発生しました。 ["The parameter \"paypal.debug\" must be defined.
","/var/www/html/var/cache/prod/ContainerYfhcaxu/EccubeProdProjectContainer.php",4286,"#0 /var/www/html/src/Eccube/Common/EccubeConfig.php(37): ContainerYfh
caxu\\EccubeProdProjectContainer->getParameter('paypal.debug')\n#1 /var/www/html/app/Plugin/PayPalCheckout/Service/PayPalService.php(160): Eccube\\Common\\E
ccubeConfig->get('paypal.debug')\n#2 /var/www/html/app/Plugin/PayPalCheckout/Controller/PaypalCheckout/CreateOrderController.php(87): Plugin\\PayPalCheckout
\\Service\\PayPalService->isDebug()\n#3 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(151): Plugin\\PayPalCheckout\\Controller\\PaypalCheckout\\Cr
eateOrderController->__invoke(Object(Symfony\\Component\\HttpFoundation\\Request))\n#4 /var/www/html/vendor/symfony/http-kernel/HttpKernel.php(68): Symfony\
\Component\\HttpKernel\\HttpKernel->handleRaw(Object(Symfony\\Component\\HttpFoundation\\Request), 1)\n#5 /var/www/html/vendor/symfony/http-kernel/Kernel.ph
p(200): Symfony\\Component\\HttpKernel\\HttpKernel->handle(Object(Symfony\\Component\\HttpFoundation\\Request), 1, true)\n#6 /var/www/html/index.php(76): Sy
mfony\\Component\\HttpKernel\\Kernel->handle(Object(Symfony\\Component\\HttpFoundation\\Request))\n#7 {main}"] [POST, /paypal/prepare-transaction, 192.168.8
9.113, http://192.168.89.141/shopping/confirm, Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.70 Sa
fari/537.36]