First, find the embed code provided by Teacher Tube for the video you want to embed. Copy this code by selecting it and pressing "Ctrl+C" on your keyboard:
Go into edit mode on your workspace by clicking the "Edit" tab.
Click the "Insert" button and select the "TeacherTube Video" plugin from the "More Plugins -> Video & Photo" category.
Paste in the embed code provided to you by TeacherTube, and click the Next button.
Click "Insert Plugin" to set the plugin, and then save the workspace page.