How to change/set ip:port proxy from clipboard in one click?

Question

Mozilla Firefox

when I turn on the proxy in the browser, in the pref.js profile file, a line is added (it's just on / off)
user_pref("network.proxy.type", 1)
here the settings themselves are
user_pref("network.proxy.http", "145.249. 105.25");
user_pref("network.proxy.http_port", 8118);
but if I manually write this line into this file, then I need the browser to reread the config.
Or how is it done/works? how to do?
I wanted to by copying the address:port of the desired proxy to the clipboard
and clicking the "magic button" - change / register this proxy, and clicking another one - disable it.
PS
how to write from the buffer to a file, I'll figure it out

Answer 1

https://addons.mozilla.org/ru/firefox/addon/proxy-...
and a bunch of similar
ps specifically about prefs.js , we already discussed it somehow;)) everything is written in the file header. it is not reread during the session, moreover, it is overwritten at the end of the sense, by the fact that in the fox settings in the RAM

// Mozilla User Preferences

// DO NOT EDIT THIS FILE.
//
// If you make changes to this file while the application is running,
// the changes will be overwritten when the application exits.
//
// To change a preference value, you can either:
// - modify it via the UI (e.g. via about:config in the browser); or
// - set it within a user.js file in your profile.

upd