502 Bad Gateway - connect() to unix:/run/php/php-fpm.sock failed about okrsw HOT 2 CLOSED

vim /etc/php-fpm.d/www.conf，
看到
; '/path/to/unix/socket' - to listen on a unix socket.
; Note: This value is mandatory.
listen = /run/php-fpm/www.sock

from okrsw.

[root@iZ8vbbykhgoo02uidpv861Z nginx]# vim error.log
2021/03/19 05:46:26 [crit] 10782#0: *259 connect() to unix:/var/run/php/php7.4-fpm.sock failed (2: No such file or directory) while connecting to upstream, client: 205.185.122.102, server: _, request: "GET /config/getuser?index=0 HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.4-fpm.sock:", host: "47.92.204.128:80"
2021/03/19 06:05:18 [error] 10782#0: *261 directory index of "/usr/share/nginx/html/" is forbidden, client: 183.12.222.152, server: _, request: "GET / HTTP/1.1", host: "47.92.204.128"

from okrsw.