Can You Put a Proxy Password in a PAC File?
PAC chooses a route; authentication happens afterward. Publishing a password in the script does not add supported automatic sign-in.
No. A standard PAC result names a proxy type, host, and port. PROXY username:[email protected]:8080 is not a portable credential-setting format.
The PAC return format selects a route. Once the browser connects to that proxy, its authentication machinery handles the challenge. Anyone able to retrieve a shared PAC can also read secrets embedded in its JavaScript, even if they are obfuscated.
Automatic sign-in needs a method supported by the browser and offered by the proxy, such as an approved integrated-authentication policy or credential manager. Otherwise the user may need to complete a prompt; hiding the prompt does not supply credentials.
A local authentication helper is another arrangement: it accepts the application's connection and logs in to an upstream proxy. Its listener access and credential storage need their own controls.
Ask the administrator for the supported method using the proxy hostname and browser details. Keep the password out of PAC examples, logs, and screenshots.