Also a problem on Nginx

Tried the rules you have in FAQ, but didn’t succeed. Is there a proper way to debug the problem? Firstly it is not working. Secondly, if it would – I still don’t want to pass every request through the script, instead would be great to serve a file if it exists. Here is my .conf

can it be related to the line where I forbid external requests to all .php?

server {
	#server name
    server_name example.com www.example.com;
	
    #local connection
    listen 127.0.0.1:81;

    #root
    root /var/www/example.com;
    index index.php;

	#gzip the text
    gzip                on;
    gzip_comp_level     9;
    gzip_min_length     512;
    gzip_buffers        8 64k;
    gzip_types text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript application/javascript image/svg+xml;
    gzip_proxied        any;

    #forbid hidden files
    location ~ /\. {
        deny all;
    }

    #forbid scripts requests
    location ~* /(?:uploads|files)/.*\.php$ {
        deny all;
    }
	#serve webp
	if ($http_accept ~* “webp”){
	add_header Vary Accept;
	rewrite ^/(.*).(jpe?g)$ /wp-content/plugins/webp-express/wod/webp-on-demand.php?source=$document_root$request_uri&wp-content=wp-content&%1 break;
	}

    #search for file
    location / {
     try_files $uri $uri/ /index.php?q=$uri&$args;
    }
	
    #slash for wp-admin
    rewrite /wp-admin$ $scheme://$host$uri/ permanent;
	
    location ~ \.php$ {
        #send to fpm
		try_files $fastcgi_script_name =404;
		
		fastcgi_keep_conn on;
		include /etc/nginx/fastcgi_params;
        fastcgi_read_timeout            3600s;
        fastcgi_buffer_size             128k;
        fastcgi_buffers                 4 128k;
		fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
		fastcgi_pass unix:/run/php/php7.1-fpm.sock;
		fastcgi_index index.php;
    }
 
}