stg27.lutest.luagent.com has an A (IPv4) record (101.227.100.177) 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.
A timeout was experienced while communicating with stg27.lutest.luagent.com/101.227.100.177: Get "http://stg27.lutest.luagent.com/.well-known/acme-challenge/letsdebug-test": dial tcp 101.227.100.177:80: i/o timeout
Trace:
@0ms: Making a request to http://stg27.lutest.luagent.com/.well-known/acme-challenge/letsdebug-test (using initial IP 101.227.100.177)
@0ms: Dialing 101.227.100.177
@10001ms: Experienced error: dial tcp 101.227.100.177:80: i/o timeout
A test authorization for stg27.lutest.luagent.com to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching http://stg27.lutest.luagent.com/.well-known/acme-challenge/kpn1n8UiQ0x9wFMvSTsR6uywTTbQu0CmVgDKEqTsQBY: Timeout during connect (likely firewall problem)