Nginx uses libmodsecurity 3 through the Nginx connector. The connector hands request data to the standalone engine; your rules remain in ModSecurity configuration files.
Minimum shape
load_module modules/ngx_http_modsecurity_module.so;
server {
modsecurity on;
modsecurity_rules_file /etc/httpd/modsecurity.d/tortix_waf.conf;
}
The exact module and configuration paths depend on the package and distribution. Verify nginx -t before reloading, then confirm that audit events are written for test traffic.