Try adding this block from your rpi3.lan:
location ~ \.(php|html)$ {
try_files $uri $document_root$fastcgi_script_name =404;
fastcgi_pass unix:/run/php-fpm/php-fpm.sock;
fastcgi_pass php-handler-www;
fastcgi_index index.php;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
include fastcgi.conf;
# prevention for httpoxy vulnerability: https://httpoxy.org/
fastcgi_param HTTP_PROXY "";
}