Now login to Joplin
 - Url: https://__DOMAIN____PATH__
 - Email: __ADMIN_MAIL__
 - Password: __ADMIN_PASS__

Then you may change the default password at this page: https://__DOMAIN____PATH__/admin/users

Then download one of these Joplin apps and configure the synchronisation with your server: https://joplinapp.org/help/install/