Hi @CelestinMbah,
You may not realize this, but you posted this to the global Instructure Community. The users here can answer a lot of questions about using Canvas and other Instructure products, but we do not have access to your Canvas account or course, and cannot help with an issue like this. You'd want to contact your teacher via whatever methods they may have made available to you (email, Canvas inbox, phone, etc) so they can help you out.
-Chris
