Volumio2 no Internet connection

Hello, I need Help to add a Web Proxy Server in Volumio 2.587 Raspberry
Other Tools mxxxxaudio have Proxy Options but I like to use Volumio2

Volumio can not connect to internet for radio/update/album art etc when behind a proxy. Type of proxy that needed to set a IP address and a port,
no username/password required. WIFI without a proxy (phone hot spot) works fine so set ups are fine.

Question/Information needed: Volumio uses a modified version of raspbian. How does Volumio connects to net? It uses wpa_supplicant.conf for keeping wifi user name/password as in regular Raspbian. Regular Raspbian uses /etc/environment file to store proxy setting for browser connection, /etc/apt/apt.conf.d file for apt-get. So more specifically, what service Volumio uses to get album art/ internet radio etc? I tried to put proxy informtion in /etc/environment file created in Volumio, which did not work.

I use this Guide but it won‘t help. apt-get update work.

theailearner.com/2018/03/13/con … xy-server/

Appreciate more information regarding this.