From what I read about Zscaler docs; Zscaler is a closed proxy, you cannot used unless you authenticate. However, I have used an explicit proxy and connected to gateway.zscloud.net on port 80. everything is working well when I access to https servers and all my https traffic goes through Zscaler, only when I access to http servers, zscaler will request authentication.
@Ahmed , i cant validate this behavior since i am using my client system and can’t do any modification in browser LAN setting.
But Zscaler cloud shouldn’t allow this behavior.