When creating an calendar appointment, it's possible to have an Online Meeting created that can be used for audio/video conferencing. Adding an online meeting to your invitation is simple: simply use the "Create Online Meeting" button on the Online Meeting card when creating the appointment.
Once clicked, you're able to configure the online meeting by setting a password, setting file upload permissions, etc. A new online meeting is created that uses the same title as the appointment's "Subject" and a link to the online meeting is automatically added to the meeting's description, so you don't even need to copy/paste anything. You simply fill out the description as you normally would, and the link is added once the invitation is sent.
Online meetings created as part of the meeting invitation follow the recurrence rules you set as well, so meetings can be used once, or as part of a recurring event.