NGINX rewrite issue for index.php - nginx

Question

I have an issue as given below.
Say I have a site example.com and I have made modifications to the rewrite logic to remove .php extensions. The code given below works fine in all the cases except for index.php
https://example.com --> Not accessible. This is not correct. It should display contents from index.php page.
https://example.com/index.php --> Displays 404 page. This is correct.
https://example.com/index --> Displays index page. This is not correct.
server {
root /usr/share/nginx/html;
# Add index.php to the list if you are using PHP
index index.php index.html index.htm;
server_name example.com www.example.com;
error_page 404 /error/custom_404;
location / {
# First attempt to serve request as file, then
# as directory, then fall back to displaying a 404.
index index.php index.html index.htm;
try_files $uri $uri/ #missing;
}
location ~* \.(jpg|jpeg|png|gif|ico|css|js|svg)$ {
expires 365d;
}
location ~* (\.php$|myadmin) {
return 404;
}
location #missing {
if (!-f $document_root$uri.php) { return 404; }
fastcgi_param SCRIPT_FILENAME "$document_root$uri.php";
fastcgi_param PATH_TRANSLATED "$document_root$uri.php";
fastcgi_param QUERY_STRING $args;
fastcgi_pass unix:/run/php/php7.0-fpm.sock;
fastcgi_index index.php;
include fastcgi_params;
}
# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
#
location ~* \.php$ {
include snippets/fastcgi-php.conf;
fastcgi_pass unix:/run/php/php7.0-fpm.sock;
}
# deny access to .htaccess files, if Apache's document root
# concurs with nginx's one
#
location ~ /\.ht {
deny all;
}
listen [::]:443 ssl ipv6only=on; # managed by Certbot
listen 443 ssl; # managed by Certbot
ssl_certificate /etc/letsencrypt/live/example.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem; # managed by Certbot
include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot
}server {
if ($host = www.example.com) {
return 301 https://$host$request_uri;
} # managed by Certbot
if ($host = example.com) {
return 301 https://$host$request_uri;
} # managed by Certbot
listen 80;
listen [::]:80;
server_name example.com www.example.com;
return 404; # managed by Certbot
}
Can someone point to where I am doing wrong?
Thanks