Using Kaltura Capture
To screen record an on screen presentation on your Mac you can install Kaltura Capture. This advantage of this method is that you can instantly upload it to your My Media folder on Moodle to share with students or to use for an assignment submission.
To install Kaltura Capture follow these instructions - https://knowledge.kaltura.com/help/download-and-install-kaltura-capture
Using Quicktime Player
Quicktime Player allows you to record your screen and microphone audio which makes it a great tool for this task.
It also comes free with every Mac.
Follow these instructions to record your presentation with Quicktime Player - https://support.apple.com/en-ca/guide/quicktime-player/qtp97b08e666/mac .
Recorded content will by default be saved to your desktop from where you can upload it to your My Media Folder on Moodle. From there you can share it in any course or to submit as an assignment.