Request failed : Web-based validation failed : Failed to request certificate :

I am having this error while creating ssl certificates, can you help me please.

request failed : Web-based validation failed : Failed to request certificate :

Traceback (most recent call last):
File “/usr/libexec/webmin/webmin/acme_tiny.py”, line 198, in
main(sys.argv[1:])
File “/usr/libexec/webmin/webmin/acme_tiny.py”, line 194, in main
signed_crt = get_crt(args.account_key, args.csr, args.acme_dir, log=LOGGER, CA=args.ca, disable_check=args.disable_check, directory_url=args.directory_url, contact=args.contact)
File “/usr/libexec/webmin/webmin/acme_tiny.py”, line 149, in get_crt
raise ValueError(“Challenge did not pass for {0}: {1}”.format(domain, authorization))
ValueError: Challenge did not pass for mail.servpcspa.com: {u’status’: u’invalid’, u’challenges’: [{u’status’: u’invalid’, u’validationRecord’: [{u’url’: u’http://mail.servpcspa.com/.well-known/acme-challenge/Ig8BR0Ri1KArcfFYQMC5F4L_xp6CHdJlIC1z1CfMAQE’, u’hostname’: u’mail.servpcspa.com’, u’addressUsed’: u’2600:3c02::f03c:92ff:fe86:cfe7’, u’port’: u’80’, u’addressesResolved’: [u’45.56.118.163’, u’2600:3c02::f03c:92ff:fe86:cfe7’]}], u’url’: u’https://acme-v02.api.letsencrypt.org/acme/chall-v3/5939451626/rNNOVg’, u’token’: u’Ig8BR0Ri1KArcfFYQMC5F4L_xp6CHdJlIC1z1CfMAQE’, u’error’: {u’status’: 403, u’type’: u’urn:ietf:params:acme:error:unauthorized’, u’detail’: u’Invalid response from http://mail.servpcspa.com/.well-known/acme-challenge/Ig8BR0Ri1KArcfFYQMC5F4L_xp6CHdJlIC1z1CfMAQE [2600:3c02::f03c:92ff:fe86:cfe7]: “\n\n404 Not Found\n\n

Not Found

\n<p”’}, u’type’: u’http-01’}], u’identifier’: {u’type’: u’dns’, u’value’: u’mail.servpcspa.com’}, u’expires’: u’2020-07-24T15:41:03Z’}

, DNS-based validation failed : Only the offical Let’s Encrypt client supports DNS-based validation