Let's Debug

Test result for pool.cg.ru using http-01

NoRecords
Fatal
No valid A or AAAA records could be ultimately resolved for pool.cg.ru. This means that Let's Encrypt would not be able to to connect to your domain to perform HTTP validation, since it would not know where to connect to.
No A or AAAA records found.
PublicSuffix
Debug
The IANA public suffix is the TLD of the Registered Domain
The TLD for pool.cg.ru is: ru
RateLimit
Debug
1 Certificates contributing to rate limits for this domain

Serial: 408156516367565907539611225677385544449968
NotBefore: 2020-07-20 00:00:22 +0000 UTC
Names: [nagios.cg.ru]

StatusIO
Debug
The current status.io status for Let's Encrypt
Operational

Submitted Jul 20 18:43:58 2020. Sat in queue for 1ms. Completed in 3s. Hide verbose information.