httpd.conf
<VirtualHost *:80>
ServerAdmin webmaster@example.com
DocumentRoot /var/www/html/irc
ServerName irc.example.com
ProxyPass /chat/ http://127.0.0.1:3989/
ProxyPassReverse /chat/ http://127.0.0.1:3989/
</VirtualHost>
First Tab: Working Iris => using http://example.com:3989/
Second Tab: Not Working Iris => using http://irc.example.com/chat/

httpd.conf
First Tab: Working Iris => using
http://example.com:3989/Second Tab: Not Working Iris => using
http://irc.example.com/chat/