I`m using Shopware and i want to disable the pagespeed plugin for my backend which is accessible trough domain.com/backend/

Now i had this location block - but it does not work, i`m getting an error in my config if i reload nginx

location /backend/ {
pagespeed off;
}

error

Reloading nginx configuration: nginx: [emerg] "pagespeed" directive is not allowed here in /etc/nginx/sites-enabled/100-shopware.domain.de.vhost:83

Does anybody has a solution ?