My Nginx Conf file.

user nginx;
worker_processes 2;

error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;

load_module "/usr/lib64/nginx/modules/nginx-ct-master/ngx_http_ssl_ct_module.c";
load_module "/usr/lib64/nginx/modules/nginx-ct-master/ngx_ssl_ct_module.c";

events {
worker_connections 4096;
multi_accept on;
}

http {
include /etc/nginx/mime.types;
default_type application/octet-stream;

log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                  '$status $body_bytes_sent "$http_referer" '
                  '"$http_user_agent" "$http_x_forwarded_for"';

access_log /var/log/nginx/access.log main;

sendfile        on;
#tcp_nopush     on;

keepalive_timeout  65;

gzip on;
gzip_disable "msie6";

gzip_vary on;
gzip_proxied any;
gzip_comp_level 6;
gzip_buffers 16 8k;
gzip_http_version 1.1;
gzip_min_length 256;
gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript application/vnd.ms-fontobject application/x-font-ttf font/opentype image/svg+xml image/x-icon;

include /etc/nginx/conf.d/*.conf;

load_module modules/ngx_ssl_ct_module.c;

include /etc/nginx/sites-enabled/*.conf;
server_names_hash_bucket_size 64;

}

from nginx-ct.

You need to compile nginx yourself to use the module (even if you use the dynamic module - nginx doesn't support out of tree builds of dynamic modules yet).

There should be plenty of guidance on how to do this on the Internet - e.g. https://www.vultr.com/docs/how-to-compile-nginx-from-source-on-centos-7 is the first one listed in Google for CentOS 7.

You'll need to add --add-module=/path/to/nginx-ct or --add-dynamic-module=/path/to/nginx-ct to the end of the ./configure command during the build.

from nginx-ct.