Update/Install behind company proxy

Hello,

I succesfully moved an existing installation to company Ubuntu server with Apache2 and MariaDB. The site works apart from Live update and Extension Repository.
I also started the Contao 4.6 setup on same server which hangs on last step, downloading contao-managed.

I suspect proxy, which company uses to access the internet.

Where do I set the proxy? Setting in the Contao settings didn't do anything, also typing it in localconfig.php didn't help. I suspect Apache. I use two virtual hosts.

Where do I have to put the proxy settings for Live Update and Extension Repository to work?

Thank you!

Ales