Blackboard Course Links are shortcuts to items or tools within the same course site.  They do not import into Canvas and will need to be recreated.

Links to different content items in the course (Quizzes/Surveys, Assignments, Files, Pages, Discussions) can be added directly into a Module

Pages, Quizzes/Surveys, Discussion Board posts, and Assignments may include links to other Pages, Quizzes/Surveys, Discussions, Assignments, Announcements, Modules, and Course Navigation.

For more info