Restoring deleted items in Canvas
To restore an item that has been deleted in a Canvas course, you will have to go to the homepage of the course that used to hold the deleted item.
This document will outline the process for an instructor to restore an item that has been deleted from a Canvas course.
Once you are on the homepage, go to the URL bar at the top of the page and type "/undelete" at the end of the page's URL. This will take you to a page showing all of the items that have been deleted from the course. From here you will be able to see the name and type of each item, and will be given the option to restore them to wherever the assignment was stored before in the course.
Note that the restored item will likely need to be republished in order to be seen by students again, and some data may have been lost during the restoration process.