Run the following command:
/root/certbot-auto certonly --manual -d voxcharta.org -d *.voxcharta.org \
--server https://acme-v02.api.letsencrypt.org/directory --preferred-challenges dns
Then, visit linode.com and add a TXT entry to voxcharta.org with the displayed key. Use dig to check that the TXT record is updated,
dig -t txt _acme-challenge.voxcharta.org +short
then hit Enter.