After configuring Tor server and installing addon, open its perferences from addons page in browser perferences (about:addons) and set the following parameters:
If you use dark theme, you can change toggle color to white by setting
svg.context-properties.content.enabled parameter to
true on about:config page.
That’s all! Now you can route browser traffic through Tor using only one button.
Please note, you will not be able to connect to .onion websites using Mozilla Firefox as it blocks such connections. Also, this will not make you anonymous. For this purpose you should use Tor Browser.