Make sure you have a course that is actually unavailable. Qwickly was designed to show only the tools that apply to you at any given moment. If you have no course to make available, you will not see that option.
If you wish to change this behavior, turn on the "Availability Toggle", which allows instructors to make courses both available AND unavailable. When this option is turned on, the Course Availability tool will always show up, even when all courses are available.