When you are accessing your WordPress website, you are facing below error,
Network Error (dns_server_failure) Your request could not be processed because an error occurred contacting the DNS server. The DNS server may be temporarily unavailable, or there could be a network problem. For assistance, contact your network support team.
1. Check your DNS servers are properly maintained (if you are registered your hosting separately with your domain)
2. Escalate to your DNS provider (hosting service provider) to check the DNS server is up and running fine.