Download the RPM
curl -O http://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
Then install it
sudo yum install epel-release-latest-7.noarch.rpm
Now you can install certbot
sudo yum install certbot
And then run it as usual
sudo certbot --debug -v --server https://acme-v02.api.letsencrypt.org/directory certonly -d 'api.bassoonic.com'