Creating a conference is a course permission. If you cannot create a conference, your institution has restricted this feature.
What are Canvas Conferences?
Canvas integrates BigBlueButton as Conferences, letting instructors and students hold virtual lectures, office hours, and student group sessions inside a course.
Canvas by Instructure includes a built-in version of BigBlueButton called Conferences, available to all Canvas customers.
Conferences are primarily used for virtual lectures, virtual office hours, and student groups. Instructors can create a conference and invite students, and students can start conferences from within their student groups.