Hi laetitia1601 - Bonjour! Welcome to the Community.
Since your account was created through Facebook--all your FB friends are already linked to your account.
What are you having trouble with? Are you having trouble sharing a track with a specific friend?
Thanks for your answer,
In fact when i click on contacts in the menu, it seems that spotify tries to load it but doesn't succed in. Si I can't see my contacts (who they are and i know i have some contacts on FB who use Spotify) and see their playlist !