Proxy doesn't seem to work

I’m new to Linux, so i don’t really understand all that terminal things so far, but Manjaro helps me overcome that

But i seems to have found a problem with mine, The proxy doesn’t seems working.

So i was using mobile internet, the speed is limited to around 50KB/s (can’t get to 100KB/s), due to its package. So i was using this android application called HTTP Injector to bypass that, anyway it does work on the phone, and on the windows through it’s Hotshare feature, using proxy. But that doesn’t work here on Manjaro, i wonder why. I noticed it right away since the connection is so slow.

Is there a way to make it work? how?

It works fine with other devices like another phone or even on this laptop on Windows 10.