Computer Configuration > Administrative Templates > Microsoft Edge Update > Proxy Server
Machine
HKLM\Software\Policies\Microsoft\EdgeUpdate
Allows you to specify a URL for a proxy auto-config (PAC) file. If you enable this policy, you can specify a URL for a PAC file to automate how Microsoft Edge Update selects the appropriate proxy server for fetching a particular website. This policy is applied only if you have specified manual proxy settings in the 'Choose how to specify a proxy server settings' policy. Don't configure this policy if you have selected a proxy setting other than manual in the 'Choose how to specify a proxy server settings' policy.