Nginx不处理php文件并保存它（php7.2-fpm）？

Question

Nginx不处理php文件并保存（php7.2-fpm）Ubuntu18：04

如何正确设置nginx以使用php7.2

/ etc / nginx / sites-available / default

   server {
    listen 80 default_server;
    listen [::]:80 default_server;

    # SSL configuration
    #
    # listen 443 ssl default_server;
    # listen [::]:443 ssl default_server;
    #
    # Note: You should disable gzip for SSL traffic.
    # See: https://bugs.debian.org/773332
    #
    # Read up on ssl_ciphers to ensure a secure configuration.
    # See: https://bugs.debian.org/765782
    #
    # Self signed certs generated by the ssl-cert package
    # Don't use them in a production server!
    #
    # include snippets/snakeoil.conf;

    root /var/www/html;

    # Add index.php to the list if you are using PHP
    index index.php index.html index.htm index.nginx-debian.html;

    server_name _;

    location / {
            # First attempt to serve request as file, then
            # as directory, then fall back to displaying a 404.
            try_files $uri $uri/ =404;
    }

    # pass PHP scripts to FastCGI server
    #
    location ~ \.php$ {
            include snippets/fastcgi-php.conf;

    #       # With php-fpm (or other unix sockets):
            fastcgi_pass unix:/var/run/php/php7.2-fpm.sock;
    #       # With php-cgi (or other tcp sockets):
    #       fastcgi_pass 127.0.0.1:9000;
    }

    # deny access to .htaccess files, if Apache's document root
    # concurs with nginx's one
    #
    location ~ /\.ht {
            deny all;
    }

}

/etc/nginx/sites-available/test.ru

 server {

 listen 80;

 listen [::]:80;

 root /var/www/test.ru/html;

 index index.php  index.html index.htm index.nginx-debian.html;

 server_name test.ru www.test.ru;

 location / {

         try_files $uri $uri/ =404;

 }

 }

sudo服务Nginx重新加载 须藤nginx -t

 nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
 nginx: configuration file /etc/nginx/nginx.conf test is successful

此行为的原因是什么？如何设置？