Nginx gzip_static_module configuration not working - nginx

Question

I am using nginx with Heroku and I wanna enable http_gzip_static_module
to serve compressed files. I compress my files manually so I have for example
bundle.js
bunsle.js.gz
I can not make this work. If I enable gzip on dynamic compression works. I am not really familiar with ngnix and I am using configs that i found on internet for use with Heroku or should I say I am using this Heroku buildpack that says it is supported.
For now only compression is important to me. I would remove extra noise if I knew what is not important. Is there something I should change? This is my config file.
daemon off;
#Heroku dynos have at least 4 cores.
worker_processes <%= ENV['NGINX_WORKERS'] || 4 %>;
events {
use epoll;
accept_mutex on;
multi_accept on;
worker_connections 1024;
}
error_log logs/nginx/error.log;
error_log logs/nginx/error_extreme.log emerg;
error_log logs/nginx/error_debug.log debug;
error_log logs/nginx/error_critical.log crit;
http {
charset utf-8;
include mime.types;
# # - Add extra mime types
types{
application/x-httpd-php .html;
}
default_type application/octet-stream;
log_format l2met 'measure#nginx.service=$request_time request_id=$http_x_request_id';
access_log logs/nginx/access.log l2met;
# # - Basic Settings
sendfile on;
tcp_nopush on;
tcp_nodelay on;
types_hash_max_size 2048;
# # - Enable open file cache
open_file_cache max=1000 inactive=20s;
open_file_cache_valid 30s;
open_file_cache_min_uses 2;
open_file_cache_errors on;
# # - Configure buffer sizes
client_body_buffer_size 16k;
client_header_buffer_size 1k;
# # - Responds with 413 http status ie. request entity too large error if this value exceeds
client_max_body_size 8m;
large_client_header_buffers 2 1k;
# # - Configure Timeouts
client_body_timeout 12;
client_header_timeout 12;
# # - Use a higher keepalive timeout to reduce the need for repeated handshake
keepalive_timeout 300;
# # - if the request is not completed within 10 seconds, then abort the connection and send the timeout errror
send_timeout 10;
# # - Hide nginx version information
server_tokens off;
# # - Dynamic gzip compression
gzip_static on;
#gzip off;
gzip_http_version 1.0;
gzip_disable "msie6";
gzip_vary on;
#gzip_min_length 20;
#gzip_buffers 4 16k;
#gzip_comp_level 9;
gzip_proxied any;
#Turn on gzip for all content types that should benefit from it.
gzip_types application/ecmascript;
gzip_types application/javascript;
gzip_types application/json;
gzip_types application/pdf;
gzip_types application/postscript ;
gzip_types application/x-javascript;
gzip_types image/svg+xml;
gzip_types text/css;
gzip_types text/csv;
gzip_types text/javascript ;
gzip_types text/plain;
gzip_types text/xml;
gzip_types text/html;
map $http_upgrade $connection_upgrade {
default upgrade;
'' close;
}
upstream nodebeats {
server unix:/tmp/nginx.socket fail_timeout=0;
keepalive 32;
}
server {
listen <%= ENV['PORT'] %>;
server_name _;
root "/app/";
location / {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection "upgrade";
proxy_pass http://nodebeats;
}
location /api {
proxy_pass http://nodebeats;
proxy_http_version 1.1;
proxy_set_header Upgrade $http_upgrade;
proxy_set_header Connection 'upgrade';
proxy_set_header Host $host;
proxy_cache_bypass $http_upgrade;
}
location /dist {
alias "/app/app-dist";
# # - 1 month expiration time
expires 1M;
access_log off;
add_header Pragma public;
add_header Cache-Control public;
add_header Vary Accept-Encoding;
}
location /offline {
alias "/app/public/offline";
# # - 1 month expiration time
expires 1M;
access_log off;
add_header Pragma public;
add_header Cache-Control public;
add_header Vary Accept-Encoding;
}
location /scripts {
alias "/app/node_modules";
# # - 1 month expiration time
expires 1M;
access_log off;
add_header Pragma public;
add_header Cache-Control public;
add_header Vary Accept-Encoding;
}
}
}