How do I access Nginx conf files as instructed by Defender and Hummingbird

I have just migrated a site to WPMU hosting.. but Defender and Hummingbird are asking me to configure server side settings which I’m not sure I have access to. I tried creating an SSH user and logging in to terminal but it has limited commands including DIR and CD :expressionless:

I also have the same demands from Hummingbird to enable Gzip commpression (shouldn’t this already be enabled on your hosting?)

The file Im asked to modify is: “/usr/local/nginx/conf/nginx.conf”