By default, all Canvas Course are created with hidden links for Tegrity Classes and the Kaltura links for My Media and Media. Unlike Canvas links, when hidden, Third Party Links do not show up grayed out in the navigation bar.
To unhide the Tegrity Classes Link, click Settings > Navigation, and drag up the link to unhide it. Be sure to click Save. You may need to scroll down to the bottom to find it. Please Do Not try to add these tool as an External Tool in a Page.