The first step is to add the certbot repository:

sudo add-apt-repository ppa:certbot/certbot

Next, update your package list:

sudo apt-get update

Next, install the certbot client for Apache:

sudo apt-get install python-certbot-apache

Run the following command and follow the prompts to renew multiple domains:

certbot --apache -d subdomain1.yourdomain.co.za -d subdomain2.yourdomain.co.za -d subdomain3.yourdomain.co.za