Vhost file location?

Where can I find vhost files in EE4?

/etc/nginx/sites-enabled/default.conf
/etc/nginx/conf.d/

or somewhere else?

EasyEngine stores all sites data in /opt/easyengine/sites
Nginx config for an individual site: /opt/easyengine/sites/example.com/config/nginx
Individual vhost configuration: /opt/easyengine/sites/example.com/config/nginx/config/nginx/conf.d/main.conf
Your own customizations: /opt/easyengine/sites/example.com/config/nginx/custom/

Some more reading is found here.