Choose the Text Box tool (by default on the Main and Text sections of the Drawing toolbar) to add captions and other text to your drawing.
Click or drag in the drawing area to place a text box with a blinking cursor, and type.
Drag the black graphic handles to size the object, or drag the center x to move it.
Use the Object Style toolbar to change the appearance of the text box itself.
Use the Text Style toolbar to change the appearance of the text.