Six buttons to the right of the hyperlink button in the Rich Content Editor, you’ll see an icon that looks like a v (or a down arrow). When you click on that one you see:

Drop Down Menu for Down Arrow Icon
Drop Down Menu for Down Arrow Icon

If you select TEDEd, you get the following search window:

TEDEd Search Window
TEDEd Search Window

Just decide which of the Embedding options you want to use and then the video is available for your students to click on and view!