How to set up input for https curl and header key?

Elastic Stack Logstash
11

Going back to domain name instead of IP address didn't throw any errors but just sat there. I removed the port after the domain name which caused 'could not read from stream : Read time out
' error. Then, I tried

input {
  http_poller {
    urls => {
	  rv_url => {
        method => get
		  url => "https://feed.source.com:443/1.0/json/A9575EEEE9F44635332E9928FD237049/server-status?auto"
		  headers => { 
		    api_key => "zBA7goakSWiEY19w1A7aHA" 
			}
		}
	}
#	request_timeout => 60
	schedule => { cron => "* * * * * UTC"}
	codec => "json"
#	metadata_target => "http_poller_metadata"
  }
}
output {
  stdout {
    codec => rubydebug
  }
}

from: https://www.elastic.co/blog/introducing-logstash-http-poller, which gave me this error:

{
      "@version"←[0;37m => ←[0m←[0;33m"1"←[0m,
    "@timestamp"←[0;37m => ←[0m2018-07-31T20:56:00.240Z,
       "message"←[0;37m => ←[0m←[0;33m"<head><title>Not authorized</title></head>"←[0m,
          "tags"←[0;37m => ←[0m[
        ←[1;37m[0] ←[0m←[0;33m"_jsonparsefailure"←[0m
    ]
}

What can I try now?