How to disable automatic installation of Firefox updates in the background?

Question

Mozilla Firefox

Yesterday I decided to switch from Vivaldi to Firefox. Firefox works much faster, other things being equal (on Windows too).

Xubuntu system 18.04. Firefox gave the message: "We just installed an update in the background. Click Restart Firefox to finish applying it." This unpleasant feature manifested itself on two machines.
Question: why does Firefox update itself, when should it do it through aptand how to get rid of it?

Answer 1

Try about:config
app.update.auto false

Answer 2

https://docs.xubuntu.org/1804/user/ru/managing-app...
Look there in the item "Check for and install updates automatically" most likely it is the automatic installation of updates. Change it to something else.