This configuration to your nginx.conf should help you.
https://gist.github.com/baskaran-md/e46cc25ccfac83f153bb
server {
listen 80;
server_name localhost;
location / {
root html;
index index.html index.htm;
}
error_page 404 /404.html;
error_page 403 /403.html;
# To allow POST on static pages
error_page 405 =200 $uri;
# ...
}