Configure presence in Skype for Business Online
The Lync presence setting for Lync Online gives people more control over who can see whether they are available, in a meeting, or out of the office. For details about Lync presence and privacy settings, see Control access to your presence information in Lync.
Choose the default presence setting for everyone in your organization
Go to Admin > Service Settings > Instant messaging, meetings and conferencing.
Under Lync presence, click the setting you want.