undefined function session_id() – nginx / php72 / php-fpm and enfold

hi,

I’m new to enfold and I tried to install the theme on my freebsd server. I found in the forum an entry that I can add
add_theme_support('avia_no_session_support');
to the function.php.

That works for me but I want to use session support as well. Can somebody provide me a working nginx / php configuration?

    location / {
        # Expiry-Header for static content
        location ~ \.(jp(e)?g|gif|css|png|js)$ {
            access_log    /usr/local/www/blog.mydomain.de/log/access_static.log main;
            expires       30d;
        }

        # php
        location ~ \.php$ {
            # if a file isn't found, 404
            try_files      $uri =404;
            fastcgi_pass   10.1.1.7:9000;
            fastcgi_index  index.php;
            fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
            fastcgi_pass_header Set-Cookie;
            fastcgi_pass_header Cookie;
            fastcgi_ignore_headers Cache-Control Expires Set-Cookie;
            include        fastcgi_params;
        }
    }

I set in the php.ini
session.save_path = "/tmp"
the directory is writeable by everyone.

I use another nginx as proxy / balancer to separate different web installation. nextcloud separate to wordpress…

server {
    ### domain names
    server_name    blog.mydomain.de;
    listen         80;

    location / {
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Protocol $scheme;
        proxy_set_header X-Forwarded-For $remote_addr;
        proxy_set_header X-Forwarded-Port $server_port;
        proxy_set_header X-Forwarded-Server $host;
        proxy_connect_timeout 3600;
        proxy_send_timeout 3600;
        proxy_read_timeout 3600;
        proxy_redirect off;
        proxy_max_temp_file_size 0;

        proxy_pass http://10.1.1.7:80;
    }
}

thank u
Steffen