Hello,

In case that you already have your SSL certificate issued you could follow the steps here on how to install an SSL certificate from a commercial certificate authority:

https://www.digitalocean.com/community/tutorials/how-to-install-an-ssl-certificate-from-a-commercial-certificate-authority

If you do not have a certificate yet, I could suggest using Let’s Encrypt together with certbot as it provides an automated way of installing the certificate and then of renewing it every 3 months automatically:

https://www.digitalocean.com/community/tutorials/how-to-secure-apache-with-let-s-encrypt-on-ubuntu-18-04

Best,
Bobby