Certbot wildcard certificate

Getting a wildcard SSL / TLS certificate from LetsEncrypt

On your server run the following:
certbot-auto certonly -d '*.domain.co.uk' -d 'domain.co.uk' --manual

You will then be asked to add a TXT record to your domain.
Edit your DNS record and add a TXT record with the host set to:

And the value as supplied by certbot-auto:

You can check when the DNS change has gone through by running:
dig -t txt _acme-challenge.domain.co.uk

Then complete the process on the command line (ie. press enter to certbot-auto)