If an assignment in Canvas allows or requires a video submission, it is best to use the Canvas Studio submissions option.
Students - when in the assignment in Canvas, choose the Studio square in the submit assignment area and follow the steps to record or upload a video into Studio. For more details, see Canvas documentation on Studio assignment submissions.
Instructors - just enable the File Upload Online submission type in your assignment to enable Studio assignment submission for students. For more details, see Canvas documentation on Studio assignment creation.