ws to wss with Plesk & Apache

Hello,

I'm trying to make a secure websocket.
When i try with ws:// it's working fine but not with wss://

I've enabled mod_proxy and mod_proxy_reverse.
Added those line to Apache https.conf
ProxyPass /wss ws://127.0.0.1:8090 retry=0 keepalive=On
ProxyPassReverse /wss ws://127.0.0.1:8090 retry=0

But still not working.

The website is using https, so FireFox won't able a connexion to ws on https (for security reasons).

Anyone have a trick to make it work ?

Fey