hain3d.duckdns.org has an A (IPv4) record (14.169.164.184) but a request to this address over port 80 did not succeed. Your web server must have at least one working IPv4 or IPv6 address.
A timeout was experienced while communicating with hain3d.duckdns.org/14.169.164.184: Get "http://hain3d.duckdns.org/.well-known/acme-challenge/letsdebug-test": context deadline exceeded
Trace:
@0ms: Making a request to http://hain3d.duckdns.org/.well-known/acme-challenge/letsdebug-test (using initial IP 14.169.164.184)
@0ms: Dialing 14.169.164.184
@10000ms: Experienced error: context deadline exceeded
A test authorization for hain3d.duckdns.org to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
14.169.164.184: Fetching http://hain3d.duckdns.org/.well-known/acme-challenge/XcRiPgGbXUZLk0CLG3V_Tk_aP0kq8qwQ-dEo0Ne31XY: Timeout during connect (likely firewall problem)