In case you missed it, here is a step by step guide from the video:
  1. Click "Insert" and "Text" or drag the text option from the toolbar on the right
  2. The textbox will appear and you can start typing in in straight away
  3. If a textbox is not selected, click it to select and edit the text
  4. Select the text to change the font, style and style as you normally would in a word processor
  5. Drag a corner or edge to resize the textbox
  6. To align the text box go to "Layout", "Align" and choose one of the options displayed