Problem when launching APM planner 2.0

Hey, Well when i launch apmplanner2.0 the message below shows up
< The current user does not have the correct permissions to access serial devices. Use “sudo adduser dialout” and then log out and in again>
i tried the solution posted here, But it didn’t work.
Any other suggestions!!

hello !
Just type sudo usermod -a -G dialout $USER to add yourself to the group dialout
Or go in parameter > users and groups > manage groups > edit dialout to add yourself.

Edit: just see that the other post give the same answer. But need :

Reboot !

Thanks a lot it worked, I used the command you gave but i didn’t get the second option can you explain more.!!