It applies to Skype for Business for Windows.
To start an unscheduled meeting (Meet Now) in Skype for Business, do the following:
1. Select the options icon.
2. Select Meet Now.
3. Select your audio settings and select Join.
4. Your meeting will start, select the members icon to add members to this meeting.
You also have the option to invite people by sending them the direct meeting link.
1. Go to the more button (...), and select Meetings Entry Info.
2. Copy the meeting link, and send it to your participants.