www.iotplayground.tk has an A (IPv4) record (126.96.36.199) 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 www.iotplayground.tk/188.8.131.52: Get http://www.iotplayground.tk/.well-known/acme-challenge/letsdebug-test: context deadline exceeded
@0ms: Making a request to http://www.iotplayground.tk/.well-known/acme-challenge/letsdebug-test (using initial IP 184.108.40.206)
@0ms: Dialing 220.127.116.11
@10000ms: Experienced error: context deadline exceeded
A test authorization for www.iotplayground.tk to the Let's Encrypt staging service has revealed issues that may prevent any certificate for this domain being issued.
Fetching http://www.iotplayground.tk/.well-known/acme-challenge/PVTM78kI7v3zT6VTnFSjjnYhtZMbJxw2pOs4_AM_RuY: Timeout during connect (likely firewall problem)