Generate a Cloudflare LetsEncrypt Certificate

Download acme and install acme

curl https://get.acme.sh | sh -s email=liam@fascinated.cc

Set the default cert provider to letsencrypt

acme.sh --set-default-ca --server letsencrypt 

Setup env vars for your cloudflare account

export CF_Token=""
export CF_Account_ID=""
export CF_Zone_ID=""

Create the cert

acme.sh --issue --dns dns_cf -d <domain>