Recast Application Manager supports using proxy, but there are some steps you need to take care of. To do this, you need PsExec tool, which you can download from here: https://docs.microsoft.com/en-us/sysinternals/downloads/psexec.
- Open command prompt as an administrator
- Change the directory to same as your PsExec.exe file (eq. cd C:\Temp)
- Open your browser with a system account: PsExec.exe -i -s -d "c:\program files\<browser_name>\<browser>.exe"
- Go to Internet Options > Connections > LAN Settings.
- Configure your proxy server address and port
- Click OK and close the browser.
- Open C:\ProgramData\Recast Software\Application Manager\PackageDownloader\PackageDownloader.xml and make sure your Proxy element is set to Default