Hi @DilrubaMoutusi,

I believe a Canvas admin would have to unconclude the course for you, according to the  How do I unconclude a course in an account? - Instructure Community - 189  guide.  You can contact your school/institution Canvas team (usually in the eLearning / IT / Digital Education area) to see if they'll unconclude for you.  If you happen to be using the free-for-teacher Canvas instance, unconcluding might not be possible as there are really no regular admins around in that instance.

Hope this info helps!

-Chris