Setting codeigniter in subfolder on nginx (ubuntu 16.04)

how to setting codeigniter in subfolder on nginx ..

step :
1) sudo gedit /etc/nginx/sites-available/defaults
2) add this script :
location /codeigniter_folder{
try_files $uri $uri/ /codeigniter_folder/index.php;
}
save.
3) sudo service nginx reload
4) open codeigniter page again.. and bingo!