A test authorization for sparkweb.net to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
DNS problem: SERVFAIL looking up TXT for _acme-challenge.sparkweb.net - the domain's nameservers may be malfunctioning
Challenge update failures for sparkweb.net in order https://acme-staging-v02.api.letsencrypt.org/acme/order/5751349/115310858
acme: error code 400 "urn:ietf:params:acme:error:dns": DNS problem: SERVFAIL looking up TXT for _acme-challenge.sparkweb.net - the domain's nameservers may be malfunctioning