Access index.html in folder without 301 redirect

The index directive and the $uri/ element of the try_files directive, has the side-effect of adding a trailing / to directory names by performing an external redirect.

To avoid the external redirect and return an appropriate index file when presented with a slash-less directory name, implement the index functionality explicitly within the try_files directive:

location / {    try_files $uri $uri/index.html $uri.php;    expires 30d;}

Notice that .php works only in the last element at this location. If you need to check for $uri/index.php (in addition to $uri.php) you can use a named location block - and move or copy your fastcgi configuration into it.

For example (based on your server block):

root /var/www/vhosts/site.com/htdocs;error_page 404 /404.php;location / {    try_files $uri $uri/index.html @php;    expires 30d;}location @php {    try_files $uri.php $uri/index.php =404;    include       fastcgi_params;    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;    ...    fastcgi_pass ...;}location = /index.php { return 301 $scheme://$host; }location = /index { return 301 $scheme://$host; }location /. { return 404; }location ~* \.php(/|$) { rewrite ^(.*)\.php $1 last; }include "ssl_offloading.inc";