Unable to issue a Let's Encrypt certificate with Let's Encrypt extension. The following error appears in Plesk:
PLESK_ERROR: Error: Could not issue a Let's Encrypt SSL/TLS certificate for example.com. Authorization for the domain failed.
Invalid response from https://acme-v01.api.letsencrypt.org/acme/authz/tJtfLEnZ8koD2Ckyz2JyRoJkjGUO1T9MSm7hFVTr2TE.
Detail: DNS problem: SERVFAIL looking up A for example.com
A test file
test.txtcreated in the domain directory
/var/www/vhosts/example.com/httpdocs/.well-known/acme-challenge/is accessible from the Internet via the URL http://example.com/.well-known/acme-challenge/test.txt.
A DNS zone of a domain has not been propagated to Let's Encrypt's DNS servers.
Wait until DNS propagation is completed. It can take up to 48 hours.
If after 48 hours the issue still persists then submit a post in LE community https://community.letsencrypt.org/.