This toolbar allows simple click-to-add HTML elements.

For the options that are simple buttons (e.g. bold, italics), one can select text and then click the button to apply the tag around the selected text.

For the options at open panels (e.g. link), open the panel first, add the url to the text box (if link), then hit Apply Link. If it's font sizing or colors, then select the text and click the size you want, e.g., xx-small.