How can users be directed through a proxy without specifying the server in the browser settings?

Question

proxy

Colleagues, tell me ways to direct users to the Internet without prescribing proxy settings in the browser. I tried the scheme: Cisco ASA and Squid via WCCP, but, unfortunately, traffic redirection via WCCP did not work. At the same time, a transparent proxy worked if it was specified in the browser settings.
But there is a task - not to register there. GPO is also not an option, unfortunately.

Answer 1

Transparent proxy and that's it...
Is Squid set to http + https ? Or how?

Answer 2

You can use WPAD .
Transparent redirection is also possible, check that squid is not going through the ASA.