php-fpm on ubuntu 20.04 with nginx - php

Question

I have installed nginx on ubuntu 20.04 server. Simple HTML sites are working fine. Later i decided to install php-fpm. I have phpinfo.php file in my /var/www/html folder with following code
<?php
phpinfo ();
?>
Now when i point to this file in my browser my browser downloads phpinfo.php file instead of showing me my PHP information page. I believe my PHP is not working or my nginx is not using or passing my request through PHP. I also believe that there is something i'm missing in default file sitting in /etc/nginx/sites-available folder. This missing part is suppose to use installed php on this server. My nginx.conf file is:
user www-data;
worker_processes auto;
pid /run/nginx.pid;
include /etc/nginx/modules-enabled/*.conf;
events {
worker_connections 768;
}
http {
sendfile on;
tcp_nopush on;
tcp_nodelay on;
keepalive_timeout 65;
types_hash_max_size 2048;
include /etc/nginx/mime.types;
default_type application/octet-stream;
ssl_protocols TLSv1 TLSv1.1 TLSv1.2 TLSv1.3; # Dropping SSLv3, ref: POODLE
ssl_prefer_server_ciphers on;
access_log /var/log/nginx/access.log;
error_log /var/log/nginx/error.log;
gzip on;
include /etc/nginx/conf.d/*.conf;
include /etc/nginx/sites-enabled/*;
}
My default file in /etc/nginx/sites-available is
server {
listen 80 default_server;
listen [::]:80 default_server ipv6only=on;
root /var/www/html;
index index.php index.html index.htm;
server_name server_domain_name_or_IP;
location / {
try_files $uri $uri/ =404;
}
error_page 404 /404.html;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /usr/share/nginx/html;
}
}