We will use lets-encrypt for a free SSL Certificate. If you've been following along with these posts then just run
sudo apt-get update
sudo snap install core; sudo snap refresh core
sudo snap install --classic certbot
sudo certbot --apache
but if you have done something different then go to lets-encrypt and choose software and system and follow the instructions as you scroll down
And that's it! Go to your website and see the small lock to the left of your search bar!