Thxs for this log.
I tested with wget (through same proxy of my browser) and I obtain a "500 Internal
Server Error" (I tested with SSLv2, SSLv3, TLSv1, TLSv1_1 and TLSv1_2 protocol) :-/
I tested on my developpment server on ou intranet (through our proxy):
$xwiki.getURLContent('https://set7z18fgf.execute-api.us-east-1.amazonaws.com/prod/?route=getClanDetails&clanTag=%23L9CGQYC')
working.
Do you need my log to make it working on myxwiki.org? If yes which one?
  The issue is
 with the HTTPS protocol used in the URL.
 In the logs of 
myxwiki.org there’s:
 Failed to retrieve content from
[
https://set7z18fgf.execute-api.us-east-1.amazonaws.com/prod/?route=getClanD…] javax.net.ssl.SSLHandshakeException:
 Received fatal alert: handshake_failure
 At this point I don’t know
 what’s the problem. We’re using httpclient in
 getURLContent() which supports HTTP over SSL out of the
 box.
 Thanks-Vincent
  
 Thxs for your help.
 Pascal B