coolab.org has an A (IPv4) record (159.203.86.156) but a request to this address over port 80 did not succeed. Your web server must have at least one working IPv4 or IPv6 address.
Get "http://coolab.org/.well-known/acme-challenge/letsdebug-test": dial tcp 159.203.86.156:80: connect: connection refused
Trace:
@0ms: Making a request to http://coolab.org/.well-known/acme-challenge/letsdebug-test (using initial IP 159.203.86.156)
@0ms: Dialing 159.203.86.156
@8015ms: Experienced error: dial tcp 159.203.86.156:80: connect: connection refused
A test authorization for coolab.org to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
159.203.86.156: Fetching http://coolab.org/.well-known/acme-challenge/p0GezCnOVBpigKpjHJ1mfLMnzHMAfK06t2xIBpWh8b0: Connection refused