Hello! If you are using an app like explainedu, the video should save/upload into your Google Drive. Then all you have to do is follow the instructions here How do I upload a video using the Rich Content Editor as an instructor?.
If you did not use an app and just recorded using the video feature on your iPad, I would still add the video to the Google Drive app on your iPad and then follow the linked instructions above. If you do not have the Google Drive App on your iPad you can always do it the old fashion way and email it to yourself, then download the video on your laptop and go from there 
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Another option you might like and might make things easier is you recording directly in Canvas using the following options...How do I record a video using the Rich Content Editor as an instructor?
You can also record and/or upload a video within the Announcements feature in Canvas.
Hope this was helpful! Please let us know if you have any further questions, we are all here to help.
All the best.
