How to add a user to a group without relogin?

Question

linux

Actually the question itself is voiced in the title of the topic.
Seems like a simple question, but I haven't been able to find an answer yet.

Answer 1

so far I have found a solution that works only for a single console:
(you need to enter a user password)
or
In principle, I found what I was looking for, but I want a more universal solution, when it would work for new consoles.

Answer 2

run in the terminal
su -s
sudo and then run the applets you need with the settings