your own production environment: centos7,openresty,php,mysql

problem: IP access is normal. Enter ip/install to display 403 Forbidden,. I can"t change the permission to / usr/local/openresty/nginx/html directory to 777. How can I solve this problem?
just found that 50x.html can also be displayed, but ip/install/index.php can not.

if I visit my ip adress/install/index.php, and download this file, how can I set up to access index.php correctly?

error.log shows

2018/06/08 10:33:18 [error] 12018-sharp12018: *334 directory index of "/usr/local/openresty/nginx/html/install/" is forbidden,

your own nginx.conf configuration:

user  root;
worker_processes  1;

-sharperror_log  logs/error.log;
-sharperror_log  logs/error.log  notice;
-sharperror_log  logs/error.log  info;

-sharppid        logs/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;

    -sharplog_format  main  "$remote_addr - $remote_user [$time_local] "$request" "
    -sharp                  "$status $body_bytes_sent "$http_referer" "
    -sharp                  ""$http_user_agent" "$http_x_forwarded_for"";

    -sharpaccess_log  logs/access.log  main;

    sendfile        on;
    -sharptcp_nopush     on;
    
    client_max_body_size 8m;    -sharp
    client_body_buffer_size 2m;  -sharp

   -sharpWAF
    lua_shared_dict limit 50m;  -sharpcc50M
    lua_shared_dict guard_dict 100m;
    lua_shared_dict dict_captcha 70m;
    lua_max_running_timers 1;
    lua_package_path "/usr/local/openresty/nginx/conf/waf/?.lua";
    init_by_lua_file "/usr/local/openresty/nginx/conf/waf/init.lua";
    access_by_lua_file "/usr/local/openresty/nginx/conf/waf/access.lua";
   

    -sharpkeepalive_timeout  0;
    keepalive_timeout  65;

    gzip  on;

    server {
        listen       80;
        listen       [::]:80 default_server;
        server_name   my ip address;
        
        -sharpcharset koi8-r;

        -sharpaccess_log  logs/host.access.log  main;

        location / {

            root    html;
            index  index.html index.htm index.php;
        }


        location /phpmyadmin {
            alias /usr/share/phpMyAdmin;
            index index.php;
         }

       location ~ /phpmyadmin/.+\.php$ {
            if ($fastcgi_script_name ~ /phpmyadmin/(.+\.php.*)$) {
             set $valid_fastcgi_script_name $1;
            }
             include fastcgi_params;
             fastcgi_pass 127.0.0.1:9000;
             fastcgi_index index.php;
             fastcgi_param SCRIPT_FILENAME /usr/share/phpMyAdmin/$valid_fastcgi_script_name;
         }

       

        -sharperror_page  404              /404.html;

        -sharp redirect server error pages to the static page /50x.html
        -sharp
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

        -sharp 
        -sharp PHP  FastCGI. FastCGI.
        -sharp Fastcgi(PHP,Python).
        location ~ \.php$ {
            -sharp 
            fastcgi_pass   127.0.0.1:9000;
            -sharp nginx()
            fastcgi_index  index.php;
            -sharp 
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            -sharp fastcgi
            include        fastcgi_params;
        }

        -sharp proxy the PHP scripts to Apache listening on 127.0.0.1:80
        -sharp
        -sharplocation ~ \.php$ {
        -sharp    proxy_pass   http://127.0.0.1;
        -sharp}

        -sharp pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
        -sharp
        -sharplocation ~ \.php$ {
        -sharp    root           html;
        -sharp    fastcgi_pass   127.0.0.1:9000;
        -sharp    fastcgi_index  index.php;
        -sharp    fastcgi_param  SCRIPT_FILENAME  /document_root$fastcgi_script_name;
        -sharp    include        fastcgi_params;
        -sharp}

        -sharp deny access to .htaccess files, if Apache"s document root
        -sharp concurs with nginx"s one
        -sharp
        -sharplocation ~ /\.ht {
        -sharp    deny  all;
        -sharp}
    }


    -sharp another virtual host using mix of IP-, name-, and port-based configuration
    -sharp
    -sharpserver {
    -sharp    listen       8000;
    -sharp    listen       somename:8080;
    -sharp    server_name  somename  alias  another.alias;

    -sharp    location / {
    -sharp        root   html;
    -sharp        index  index.html index.htm;
    -sharp    }
    -sharp}


    -sharp HTTPS server
    
    server {
        listen  443 ssl http2;
        
        server_name  my ip address;
        charset  utf-8;
        ssl on;
        default_type  text/plain;
        
       
       

       ssl_session_cache    shared:SSL:1m;
       ssl_session_timeout  5m;
       ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

       ssl_ciphers ECDHE-RSA-AES128-GCM-SHA256:HIGH:!aNULL:!MD5:!RC4:!DHE;
       ssl_prefer_server_ciphers  on;

       location / {
            root   html;
           index  index.html index.htm index.php;
        }

         location ~ /phpmyadmin/.+\.php$ {
            if ($fastcgi_script_name ~ /phpmyadmin/(.+\.php.*)$) {
             set $valid_fastcgi_script_name $1;
            }
             include fastcgi_params;
             fastcgi_pass 127.0.0.1:9000;
             fastcgi_index index.php;
             fastcgi_param SCRIPT_FILENAME /usr/share/phpMyAdmin/$valid_fastcgi_script_name;
         }

       location ~ \.php$ {
            -sharp 
            fastcgi_pass   127.0.0.1:9000;
            -sharp nginx()
            fastcgi_index  index.php;
            -sharp 
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            -sharp fastcgi
            include        fastcgi_params;
        }


   }

}