Update README.md

File translation via Apache proxy needs "ProxyPreserveHost On", which is "Off" on some distributions (RHEL8 for instance). Else window.location.host will point to the container IP instead of the host.

README.md

@@ -343,7 +343,8 @@ Remove `#` on the ErrorLog and CustomLog lines to log requests.
     
     ProxyPass / http://127.0.0.1:5000/
     ProxyPassReverse / http://127.0.0.1:5000/
-
+    ProxyPreserveHost On
+   
     SSLEngine on
     SSLCertificateFile /etc/letsencrypt/live/[YOUR_DOMAIN]/fullchain.pem
     SSLCertificateKeyFile /etc/letsencrypt/live/[YOUR_DOMAIN]/privkey.pem