Text Compression shows zero in GT Metrix

Hi,

Im having this problem of Enable compression in GT Metrix Performance as listed below. I have total control over the server and its configuration files. Can you suggest if I am missing something here? I'm just short of this last thing where I can speed up the site. I tried googling and changing some parameters and haven't had any success. I'll be obliged if you can help me with this.

https://gtmetrix.com/reports/hetalkamdar.com/knFyLZc1

And this is the Ubuntu 16.04 nginx server configuration file contents:

user nginx;
worker_processes 1;

error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

events {
worker_connections 1024;
}

http {
include /etc/nginx/mime.types;
default_type application/octet-stream;

log_format main '$remote_addr - $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" '
'"$http_user_agent" "$http_x_forwarded_for"';

access_log /var/log/nginx/access.log main;

sendfile on;
#tcp_nopush on;

keepalive_timeout 65;

#gzip on;
##
# Gzip Settings
##

gzip on;
gzip_disable "msie6";

gzip_vary on;
gzip_proxied any;
gzip_comp_level 6;
gzip_buffers 16 8k;
gzip_http_version 1.1;
gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;

include /etc/nginx/conf.d/*.conf;
}
~