Insert a text box (via the button + Component→Text) and place it where you want the question to be. This is an additional advantage: because you are using a text box, it can now be anywhere in the top space, and you are no longer bound by the default position.
Put the text in the text box and decide what text format you want. The standard keys of your operating system also work in LessonUp. For example, use keys CTRL+B (Apple: CMD+B) for bold, CTRL+I (Apple: CMD+I) for italic, etc.
Good to know: by the way, the grey word 'question', as visible in the image above, will not be shown during the lesson.