Forgot to setup MariaDB at the begining of NextCloud, How can I change it?

Hi All,

During the installation of NextCloud, I forgot to specify the database, I think I’m on sqlite3 now but I want to go to Mariadb. How can I change this? Is it important?

I suppose I need to follow this, but it’s a bit complicated…
https://docs.nextcloud.com/server/25/admin_manual/configuration_database/db_conversion.html

Regards!