CertBot not working

Hello!

I'm maked sertificate in carbonio admin panel in our site mail.kolizei.org and now trying to configure certbot to renew this sertificate automaticly, but

root@mail:/home/marat# certbot --nginx
Saving debug log to /var/log/letsencrypt/letsencrypt.log
The nginx plugin is not working; there may be problems with your existing configuration.
The error was: NoInstallationError("Could not find a usable 'nginx' binary. Ensure nginx exists, the binary is executable, and your PATH is set correctly.")

I know that

root@mail:/home/marat# ps -ef | grep nginx
carboni+ 757 1 0 14:38 ? 00:00:00 /usr/bin/carbonio-prometheus-nginx-exporter --nginx.scrape-uri= https://localhost/nginx_status  --no-nginx.ssl-verify
zextras 3323 1 0 14:39 ? 00:00:00 nginx: master process /opt/zextras/common/sbin/nginx -c /opt/zextras/conf/nginx.conf
zextras 3324 3323 0 14:39 ? 00:00:00 nginx: worker process
zextras 3325 3323 0 14:39 ? 00:00:00 nginx: worker process
zextras 3326 3323 0 14:39 ? 00:00:00 nginx: worker process
zextras 3327 3323 0 14:39 ? 00:00:00 nginx: worker process
zextras 4568 1 0 14:39 ? 00:00:00 /usr/bin/perl -w /opt/zextras/libexec/zmstat-nginx
root 52463 30633 0 15:43 pts/0 00:00:00 grep --color=auto nginx

and

# NGINX POP/IMAP proxy configuration file for use with Zimbra
#

working_directory /opt/zextras;
include /opt/zextras/conf/nginx/includes/nginx.conf.main;
include /opt/zextras/conf/nginx/includes/nginx.conf.memcache;
include /opt/zextras/conf/nginx/includes/nginx.conf.zmlookup;
include /opt/zextras/conf/nginx/includes/nginx.conf.mail;
include /opt/zextras/conf/nginx/includes/nginx.conf.web;
include /opt/zextras/conf/nginx/includes/nginx.conf.stream;

# Don't edit the below comment

#__SUCCESS__

How can I configure certbot properly?