I had installed letsencrypt ssl as per this tutorial and these were working fine, however when I tried to install new certificate I got following error
$ sudo certbot --nginx -d vatadya.com -d www.vatadya.com Saving debug log to /var/log/letsencrypt/letsencrypt.log The requested nginx plugin does not appear to be installed
I reinstall PPA from repository ppa:certbot/certbot and reinstalled “python-certbot-nginx”, still it did not resolved the problem. Finally, following installation resolved the error.
$ sudo python3.6 -m pip install certbot-nginx
Once this was installed, following command worked fine
$ sudo certbot --nginx -d example.com -d www.example.com