After I installed SSL follow link:
https://www.vultr.com/docs/install-lets-encrypt-ssl-on-one-click-wordpress-app

root@havi_host:~# service nginx restart
Job for nginx.service failed because the control process exited with error code.
See "systemctl status nginx.service" and "journalctl -xe" for details.
root@havi_host:~#
root@havi_host:~# journalctl -xe
Apr 13 14:02:39 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:443 failed (98: Address alr
Apr 13 14:02:39 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address alre
Apr 13 14:02:39 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:443 failed (98: Address alr
Apr 13 14:02:40 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address alre
Apr 13 14:02:40 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:443 failed (98: Address alr
Apr 13 14:02:40 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address alre
Apr 13 14:02:40 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:443 failed (98: Address alr
Apr 13 14:02:41 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address alre
Apr 13 14:02:41 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:443 failed (98: Address alr
Apr 13 14:02:41 havi_host nginx[31567]: nginx: [emerg] still could not bind()
Apr 13 14:02:41 havi_host systemd[1]: nginx.service: Control process exited, code=exited status=1
Apr 13 14:02:41 havi_host systemd[1]: nginx.service: Failed with result 'exit-code'.
Apr 13 14:02:41 havi_host systemd[1]: Failed to start nginx - high performance web server.

root@havi_host:~# systemctl status nginx.service
● nginx.service - nginx - high performance web server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Mon 2020-04-13 14:02:41 UTC; 59s ago
     Docs: http://nginx.org/en/docs/
  Process: 31013 ExecStop=/bin/kill -s TERM $MAINPID (code=exited, status=0/SUCCESS)
  Process: 31567 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=1/FAILURE)
 Main PID: 30921 (code=exited, status=0/SUCCESS)

Apr 13 14:02:40 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address alre
Apr 13 14:02:40 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:443 failed (98: Address alr
Apr 13 14:02:40 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address alre
Apr 13 14:02:40 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:443 failed (98: Address alr
Apr 13 14:02:41 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address alre
Apr 13 14:02:41 havi_host nginx[31567]: nginx: [emerg] bind() to 0.0.0.0:443 failed (98: Address alr
Apr 13 14:02:41 havi_host nginx[31567]: nginx: [emerg] still could not bind()
Apr 13 14:02:41 havi_host systemd[1]: nginx.service: Control process exited, code=exited status=1
Apr 13 14:02:41 havi_host systemd[1]: nginx.service: Failed with result 'exit-code'.
Apr 13 14:02:41 havi_host systemd[1]: Failed to start nginx - high performance web server.
...skipping...
● nginx.service - nginx - high performance web server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Mon 2020-04-13 14:02:41 UTC; 59s ago
     Docs: http://nginx.org/en/docs/
  Process: 31013 ExecStop=/bin/kill -s TERM $MAINPID (code=exited, status=0/SUCCESS)
  Process: 31567 ExecStart=/usr/sbin/nginx -c /etc/nginx/nginx.conf (code=exited, status=1/FAILURE)
 Main PID: 30921 (code=exited, status=0/SUCCESS)