Jorge yes it is Thats the reason of my question i have installed because i need language or others things but when i go to see if it change i saw not change and need install again to see it apply
All you do to install extensions is open up SSH from flarum root, type
composer require developername/extensionname
You then need to log on to your flarum as a admin, go intot he admin panel, and activate the extension
to update, simply type in
composer update developername/extensionname
sometimes you may have to run the following as well after updating.
php flarum migrate
php flarum cache:clear