To activate the DesignPLUS tools for additional Canvas content options, please do the following.
Login to Canvas
Navigate to a course
Create a new page (or click edit on an existing page). While still in the editing function use the keystroke combo Alt + Shift + D to make the toolbar display on the right hand side of your screen.
Click on the gear icon (Design Tools Setting) on the right hand side of the top of the toolbar.
Select the toggle to Show Launch button.
Exit out of Design Tools toolbar.
You'll now had an icon available to click on to launch the tool whenever you're editing a page in Canvas.