This guide assumes you have your public DNS hosted with CloudFlare.

On Ubuntu 20.04, install acme.sh

git clone https://github.com/acmesh-official/acme.sh.git

sudo mv acme.sh /var/acme

Append export PATH=$PATH:/var/acme to the end of /etc/profile.d/apps-bin-path.sh

sudo acme.sh --install

sudo vi /var/acme/dnsapi/dns_cf.sh

Get your Key from https://dash.cloudflare.com/profile Add the following to the top

export CF_Key="aiwilwejif9839282ffnnd032jd9dj2039je9"
export CF_Email="username@example.com"
export CF_Token="IDJDIEW9N29FHSKSOksidjfniv838373hdndikcw"
export CF_Account_ID="aasdfawef9234r0923u90jfhf8923023"
export CF_Zone_ID="68aw4ef384asef834ase38f4ase38f48"

You may also have to run those commands on the CLI before running this command.

acme.sh --issue --dns dns_cf -d domain.com -d www.domain.com