Proxy Passthrough
Supported on: Firefox 60 or later, Firefox 60 ESR or later
Registry
HKLM
Software\Policies\Mozilla\Firefox\Proxy HKCU
Software\Policies\Mozilla\Firefox\Proxy Options
Passthrough text Description
If this policy is enabled, the proxy settings are bypassed for the locations specified. If this policy is disabled or not configured, Firefox does not bypass the proxy.