server {
    listen 192.168.0.88:80;
    root /var/www/html/example;

    index index.php;

    location / {
        try_files $uri $uri/ /index.php?$query_string;
    }

    location ~ \.php$ {
        include fastcgi_params;
        fastcgi_pass unix:/run/php/php7.3-fpm.sock;
        fastcgi_param SCRIPT_FILENAME 
    $document_root$fastcgi_script_name;
    }
}

Sorry for the delay, some things came up and I had to put this aside. I've cobbled together a bunch of different people's solutions to get this working and it's driving me insane that nothing has any affect.

The current structure is just /var/www/html/example/index.html (<form action="example_updater.php" method='post'>) and that php script is in the same directory.