How can I create custom 503 and 404 error page?
what about creating a 404 in your theme / plugin: `Resources/views/storefront/page/error/error-404.html.twig` ?
how to link to the new html.twig that created by yourself?
I tried to add a controller.php to my theme and configured route.xml and services.xml, but it still can't configure it properly.
You can create it : content - shopping experience - shop Pages
Create new one "shop page"
Then go to settings - shop - basic informations