Thank you very much for your answer.
I still haven't been able to fix the problem.
The document that you indicate is outdated.
As of Mautic 3, the "app" folder changes to "bin"
So the update command would be:
sudo su daemon -s /bin/bash -c "installdir/php/bin/php installdir/apps/mautic/htdocs/bin/console mautic:update:apply -e prod"
Also, the command to clear cache doesn't work either.
Still, I can't find a solution for my situation.