b24.vplab.ru has an AAAA (IPv6) record (2a03:6f01:1:7f99::2) but a test request to this address over port 80 did not succeed. Your web server must have at least one working IPv4 or IPv6 address. You should either ensure that validation requests to this domain succeed over IPv6, or remove its AAAA record.
Get "http://b24.vplab.ru/.well-known/acme-challenge/letsdebug-test": dial tcp [2a03:6f01:1:7f99::2]:80: connect: no route to host
Trace:
@0ms: Making a request to http://b24.vplab.ru/.well-known/acme-challenge/letsdebug-test (using initial IP 2a03:6f01:1:7f99::2)
@0ms: Dialing 2a03:6f01:1:7f99::2
@2120ms: Experienced error: dial tcp [2a03:6f01:1:7f99::2]:80: connect: no route to host
A test authorization for b24.vplab.ru to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
94.228.127.153: Fetching https://b24.vplab.ru/.well-known/acme-challenge/K4hmKWqqyk2K35bVCwID4KYaVprTk1pp2Mae20Y-bpg: Error getting validation data