At this time, Camtasia videos with interactivity (quizzes) are not supported in myCourses.
Here are some alternative solutions:
Pose a question as part of the video script and/or slide deck. Stay silent for a few moments for students to reflect on their own. Then pick back up explaining the answer. The question/quiz won't get graded but the method will still engage students actively.
Place the video in a myCourses file (page). Review Uploading & Inserting Video using myCourses for details. On the same file (page) as the video, indicate to students that a quiz about the video appears on the next page. Then add a short quiz using the Quizzing tool. You can choose to have this be part of a gradebook or not.