Confirm FF browser/devices are using the server

New here. Is there a way to confirm that the devices using FF are now going through the server? Thx!

I’m not sure what you’re asking. Firefox is on your client device, and does not go through the server. What’s on the server goes through the server. What’s on the server can be accessed by a client devices. You can tell if you’re accessing the server because it’ll be in the URL bar of the browser.