1. Gnome GUI 

2.  Same 

lake@localhost:~$ export  |grep htt
declare -x HTTP_PROXY="http://10.24.1.1:8080/"
declare -x http_proxy="http://10.24.1.1:8080/"
lake@localhost:~$ export  |grep   proxy
declare -x http_proxy="http://10.24.1.1:8080/"
declare -x no_proxy="localhost,127.0.0.0/8,::1"

3. Ubuntu apt proxy, works OK for WSL also!!

lake@M5273296:~$ sudo  cat       /etc/apt/apt.conf
Acquire::http::proxy "http://10.10.5.18:8080/";
Acquire::https::proxy "https://10.10.5.18:8080/";
Acquire::ftp::proxy "ftp://10.10.5.18:8080/";
Acquire::socks::proxy "socks://10.10.5.18:8080/";

4. Git proxy 

lake@localhost:~$ cat .gitconfig 
[user]
email = lake.hu@outlook.com
name = Lake
[core]
editor = vim
[color]
ui = auto
[alias]
        logall = log --graph  --pretty=oneline  --all    --abbrev-commit    --decorate
lg = log --color --graph --pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' --abbrev-commit


[push]
default = matching
 
[https]
proxy = 10.24.1.1:8080
[http]
proxy = 10.24.1.1:8080
lake@localhost:~$