Lets Encrypt is a nonprofit Certificate Authority providing TLS certificates. If you use this service I recommend you donate.
Certbot helps you install the certificates and keep them updated.
WordPress is probably how you host your website. If you’re running WordPress MU on apach2 here are some LPT’s.
- Since you don’t have a vhost file (/etc/apache2/sites-available/example.conf) for each MU site you’ll need to make one.
- Certbot will use that to add the certificate information and enable SSL/TLS certificate.
Create a conf file for each vhost you wish to add a certificate to.
Follow the instructions here: https://certbot.eff.org/instructions to install certbot.
Once installed you can add the certificate for each domain by issuing this command from the CLI.
sudo certbot –apache -d example.com -d www.example.com