504 Gateway Time-out --- 2021-08

504 Gateway Time-out
The gateway did not receive a timely response from the upstream server or application.

Powered by Tengine

nginx 和php-fpm配置文件配置都已修改，打开网站还是超时

这个是安全组端口问题，
如果你的服务器是阿里云服务器，可以去阿里云安全组将80端口添加进去；然后你发现网站可以打开了；
完美解决。