Issues with nginx configuration

[l0rd-v0ldem0rt]

when i use your sample nginx conf file (oauth.conf) i get some "nginx: [emerg] "upstream" directive is not allowed here in /etc/nginx/nginx.conf:1
nginx: configuration file /etc/nginx/nginx.conf test failed"

i am using the same sample oauth.conf file which is there at nginx/oauth.conf

upstream app {
server unix:///opt/sock/oauth.sock;
}

server {
listen 80 default_server;
listen [::]:80 default_server;

    server_name _;
    return 301 https://$host$request_uri;

}