Let's Debug

Test result for buyerfb.ru using http-01

buyerfb.ru has an AAAA (IPv6) record (2a03:6f00:5:1::b035:a32d) 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.
A timeout was experienced while communicating with buyerfb.ru/2a03:6f00:5:1::b035:a32d: Get http://buyerfb.ru/.well-known/acme-challenge/letsdebug-test: dial tcp [2a03:6f00:5:1::b035:a32d]:80: i/o timeout

Trace:
@0ms: Making a request to http://buyerfb.ru/.well-known/acme-challenge/letsdebug-test (using initial IP 2a03:6f00:5:1::b035:a32d)
@0ms: Dialing 2a03:6f00:5:1::b035:a32d
@10000ms: Experienced error: dial tcp [2a03:6f00:5:1::b035:a32d]:80: i/o timeout
A test authorization for buyerfb.ru to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching https://buyerfb.ru/.well-known/acme-challenge/nSXM0JgIoSdajbaUC_saQ3HSbn1THFe2C2tgk6n2xAE: Timeout during connect (likely firewall problem)
Debug
Requests made to the domain
Request to: buyerfb.ru/2a03:6f00:5:1::b035:a32d, Result: [Address=2a03:6f00:5:1::b035:a32d,Address Type=IPv6,Server=,HTTP Status=0], Issue: AAAANotWorking
Trace:
@0ms: Making a request to http://buyerfb.ru/.well-known/acme-challenge/letsdebug-test (using initial IP 2a03:6f00:5:1::b035:a32d)
@0ms: Dialing 2a03:6f00:5:1::b035:a32d
@10000ms: Experienced error: dial tcp [2a03:6f00:5:1::b035:a32d]:80: i/o timeout

Request to: buyerfb.ru/176.53.163.45, Result: [Address=176.53.163.45,Address Type=IPv4,Server=nginx,HTTP Status=301,Number of Redirects=1,Final HTTP Status=200], Issue:
Trace:
@0ms: Making a request to http://buyerfb.ru/.well-known/acme-challenge/letsdebug-test (using initial IP 176.53.163.45)
@0ms: Dialing 176.53.163.45
@226ms: Server response: HTTP 301 Moved Permanently
@226ms: Received redirect to https://buyerfb.ru/.well-known/acme-challenge/letsdebug-test
@226ms: Dialing 176.53.163.45
@708ms: Server response: HTTP 200 OK

Debug
A and AAAA records found for this domain
buyerfb.ru. 0 IN A 176.53.163.45
buyerfb.ru. 0 IN AAAA 2a03:6f00:5:1::b035:a32d
Challenge update failures for buyerfb.ru in order https://acme-staging-v02.api.letsencrypt.org/acme/order/5751349/44299120
acme: error code 400 "urn:ietf:params:acme:error:connection": Fetching https://buyerfb.ru/.well-known/acme-challenge/nSXM0JgIoSdajbaUC_saQ3HSbn1THFe2C2tgk6n2xAE: Timeout during connect (likely firewall problem)
Debug
The IANA public suffix is the TLD of the Registered Domain
The TLD for buyerfb.ru is: ru
Debug
The current status.io status for Let's Encrypt
Operational

Submitted Aug 8 06:11:55 2019. Sat in queue for 6ms. Completed in 25s. Hide verbose information.