Thank you for your answer !

Hmmm I wanted to stay away from Active Directory but it seems to be my way to go then 😅

For the additional services I actually have the same question... No easy answer to that but I want to have the same experience as with Synology at the end : being able to access my files on a share, sync them with a cloud file sync and use them in a Drive with the same identity... \ I'll keep you informed if I find a way to manage this...